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Standard User adslmax
(knowledge is power) Mon 14-Nov-16 22:35:40
Print Post

Openreach to rollout 3dB target SNRm for FTTC next year


[link to this post]
 
1.2.2
VDSL2 noise margins
Currently the default target downstream noise margin is set to 6dB.
From March 2017 the target downstream noise margin shall be set to either 3, 4, 5 or 6dB
the actual value shall be determined by the Dynamic Line Management (DLM) algorithm based on line stability.

http://www.btplc.com/sinet/SINs/pdf/498v7p2a.pdf
Standard User Toonshorty
(member) Mon 14-Nov-16 22:42:06
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Great news for those on stable, but longer lines.
Standard User adslmax
(knowledge is power) Mon 14-Nov-16 22:44:49
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Toonshorty] [link to this post]
 
Based on our observations speed increases are roughly in line with the following figures.

~ For existing Sync speeds of around 20Mbps - each 3dB is worth 3Mbps
~ For existing Sync speeds of around 40Mbps - each 3dB is worth 6Mbps
~ For existing Sync speeds of 60Mbps or more - each 3dB is worth 11Mbps.

BT wholesale ADSL (copper) lines already have a 3dB profile available to them. Obviously this increase wont make any difference if you are already syncing at the maximum speed ie 80Mbps or 40Mbps if you are on a 40/10 or 40/2 product.


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Standard User RobertoS
(elder) Mon 14-Nov-16 23:05:02
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Good find Max. Thanks smile.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 57825/13835kbps @ 600m. - BQM
Standard User adslmax
(knowledge is power) Mon 14-Nov-16 23:08:11
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Actually it was kitz who spotted this.
Standard User RobertoS
(elder) Mon 14-Nov-16 23:11:43
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Thanks for clarifying as well smile. She's a star. Probably knew before the SIN was updated wink.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 57825/13835kbps @ 600m. - BQM
Standard User adslmax
(knowledge is power) Mon 14-Nov-16 23:15:24
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Yep. But sadly Target 3dB SNRm won't benefit me at all. Stayed with 80/20 (wish openreach uncapped 80/20 for the line to go faster as it support to the maximum Attainable Rate)

Edited by adslmax (Mon 14-Nov-16 23:16:55)

Standard User lee111s
(experienced) Mon 14-Nov-16 23:51:57
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Unlikely to happen with G.fast around the corner. If people close to the cab could get say 120meg with VDSL2 unrestricted then they're not going to pay the premium for 160meg. However, a doubling of the speed from 80 to 160 by upgrading to G.fast will be more appealing and appear as "better value for money".
Standard User Icaras
(experienced) Tue 15-Nov-16 07:21:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
This has been testing for a while in certain areas. I've yet to see it on a line though presumably wasn't in my area.
Standard User RobertoS
(elder) Tue 15-Nov-16 09:38:27
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
On my service, on a stable line with the connection speeds you see in my sync, I'll be quite pleased to see this.

Relatively few people are close enough to get 80/20, and many in 40/n can't even get that. I'll be quite surprised in G.Fast comes in free.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 57825/13835kbps @ 600m. - BQM
Standard User lee111s
(experienced) Tue 15-Nov-16 10:29:31
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
I didn't mean G.fast would be free.

If someone is on 80/20 and want more speed, then I imagine they'd be more likely to pay the premium for G.Fast than if they were already getting say 110mbps from an unrestricted VDSL connection.
Standard User Nightglow
(member) Tue 15-Nov-16 10:53:00
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
Would be nice if they gave use a free speed increase, change profile from 80/20 to 120/20, then you pay extra for 160/20 & upwards.
And also tweak lower profile say to 60/20 to help those on the lower speeds, I kmow a few who can't get 80/20, but could get around 57/15.
Administrator MrSaffron
(staff) Tue 15-Nov-16 11:00:50
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
There is a potential scenario where a VDSL2 cab runs out of ports but G.fast ports are available, and they might move people across to free up VDSL2 capacity. Whether that would happen no idea but the wholesale and EOI requirements make that sort of thing harder

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User lee111s
(experienced) Tue 15-Nov-16 11:08:26
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
Not a very good business model.
Standard User kasg
(knowledge is power) Tue 15-Nov-16 11:38:52
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
I guess this could benefit me. My SNRM hovers around 5dB and my sync is over 4Mbps higher than my attainable, which is presumably based on 6dB.

Kevin

plusnet Unlimited Fibre Extra - sync 66999/19999 (banded) at around 450m - BQM
Using OpenDNS
Domains and web hosting with TSOHOST
Standard User 23Prince
(committed) Tue 15-Nov-16 11:46:24
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
In reply to a post by lee111s:
I didn't mean G.fast would be free.

If someone is on 80/20 and want more speed, then I imagine they'd be more likely to pay the premium for G.Fast than if they were already getting say 110mbps from an unrestricted VDSL connection.


Well that's pretty much the way it's been on Virgin for a long time when they did free boosts but also offered higher tiers, If BT went that way I think it would be a very good business model to adopt
Standard User RobertoS
(elder) Tue 15-Nov-16 11:47:53
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
BT Consumer offer 55/10. Not as well as, but instead of, 40/10.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 57825/13835kbps @ 600m. - BQM
Standard User lee111s
(experienced) Tue 15-Nov-16 11:52:49
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: 23Prince] [link to this post]
 
Virgin operate their own network AND bill end users.

Openreach is completely different.
Standard User RobertoS
(elder) Tue 15-Nov-16 12:03:14
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
Openreach builds where its customers, the Communications Providers, want it to. Those Communications Providers being BT Wholesale, Sky, TalkTalk and Vodafone. Plus a few small fry who do not use any of those.
BT is the largest fixed broadband provider in the UK, with a market share of 31 per cent. Sky and Virgin Media both have a market share of about 20 per cent, while TalkTalk has a 15 per cent share and EE has 3 per cent.
That's for mid-2015, according to the Financial Times.

BT Wholesale and Openreach are part of BT Group, and it is unrealistic to think pricing structures are not discussed at Group level, even if BT Wholesale is excluded from the discussion.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 57825/13835kbps @ 600m. - BQM
Standard User lee111s
(experienced) Tue 15-Nov-16 12:36:48
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
I stand by my point that it's very unlikely that VDSL2 on the Openreach network will go above 80/20.
Standard User Icaras
(experienced) Tue 15-Nov-16 15:10:00
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
There is a potential scenario where a VDSL2 cab runs out of ports but G.fast ports are available, and they might move people across to free up VDSL2 capacity. Whether that would happen no idea but the wholesale and EOI requirements make that sort of thing harder


That doesn't sound like something Openreach would do, unlikely I think.
Standard User Ignitionnet
(knowledge is power) Tue 15-Nov-16 21:57:58
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
I can't even begin to describe how excited I am by this.

BT are really pushing the envelope here. State of the art a decade ago.
Standard User Chrysalis
(legend) Tue 15-Nov-16 22:40:37
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Ignitionnet] [link to this post]
 
I am happy but also find it comical for the reasons you said.

Its took them about 4 years to rollout g.inp on hauwei from first vdsl cabinet deployment.
Its still not rolled out on ECI even tho g.inp has been around for almost a decade.

5 years into FTTC they decide they can do 3db profiles, and if ECI doesnt get a working g.inp this upcoming spring these profiles are likely to further widen the gap between ECI and hauwei on performance as its way easier to achieve a stable 3db with g.inp.

smile

Really fast decision making at BT towers smile

My line currently on 4.6db snrm has comparable error rates to 6.4db tho, so I wonder if I can hold out the sync till next march with further crosstalk dropping it to around 3db and BT drop my target snrm I can then keep my sync speed. Fun times smile

Sky Fibre Pro BQM - IPv4 BQM - IPv6

Edited by Chrysalis (Tue 15-Nov-16 22:44:57)

Standard User smallal
(newbie) Tue 20-Dec-16 11:54:05
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
Chatting to a Kellys engineer he told me the strategy for the 3db profile is so BT can offer a speed boost for infinity 2 customers following the upgrade to infinity 1. Scuttlebutt is it will be up to 100mb, which also means offering a speed directly comparable to Virgins package.
Standard User baby_frogmella
(fountain of knowledge) Tue 20-Dec-16 12:56:05
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: smallal] [link to this post]
 
I wouldn't treat a Kelly's 'Engineer' words as gospel because they're usually full of <insert expletive here>

°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
TalkTalk Business 80/20
Netgear R9000 X10 running OpenWRT
My Broadband Quality Monitor
°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°°
Standard User witchunt
(member) Tue 20-Dec-16 16:39:00
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: baby_frogmella] [link to this post]
 
I wouldn't treat a Kelly's 'Engineer' words as gospel because they're usually full of <insert expletive here

Superb smile
Standard User Ignitionnet
(knowledge is power) Tue 20-Dec-16 18:29:03
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
In reply to a post by Nightglow:
Would be nice if they gave use a free speed increase, change profile from 80/20 to 120/20, then you pay extra for 160/20 & upwards.
And also tweak lower profile say to 60/20 to help those on the lower speeds, I kmow a few who can't get 80/20, but could get around 57/15.


Free upgrades are very difficult for Openreach. Would harm the business case for G.fast too. They are going to have a hard enough time trying to prise open the vice-like wallet of the average UK consumer to get then to part with more cash without reducing the difference between the products more.

Sky and TalkTalk would probably go to Ofcom with complaints that Openreach were overcharging for 80/20 if they were to offer more for free.

A non-starter I suspect.
Standard User JHo1
(member) Tue 20-Dec-16 18:30:34
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: witchunt] [link to this post]
 
I liked the quotation marks. Subtle. smile

John
Standard User planetf1
(experienced) Tue 10-Jan-17 17:02:04
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: JHo1] [link to this post]
 
I'm still on my seemingly "stuck" 35M profile, it's been that way for around 9 months now, after a failed attempt to use a HH5a as VDSL modem, as well as trying a new router (which was better) got DLMs attention.

My link is solid now for 50 days -- it's only gone down through powercut or me moving kit (which I leave off for 30 mins+ now)

34999 7.7dB / 6995 7.4dB

I wonder if the shift to potential 3/4/5 dB will release me from 34999. So far I've not put the effort into raising a fault report/visit, and indeed whether I will or not may depend on how long the new virgin cable infrastructure being deployed here (cabs/cables all in in my road in mid Dec, no service yet) takes before it's offered and I go 200 or 300 Mbps.
Standard User WWWombat
(knowledge is power) Wed 11-Jan-17 17:11:27
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: planetf1] [link to this post]
 
In theory, the philosophy that Openreach ought to employ would be:
- reduce target SNRM
- monitor resulting error rates
- reduce further if error rate is green; stop reducing if error rate is amber; increase back if error rate is red.

Lines that have been banded from high error rates are unlikely to be able to stomach any reduction in target SNRM, as it would cause extra errors. In fact banding can be considered as an alternative method to increasing the target SNRM (in your case to 7.5dB).

IMHO, DLM has been particularly aggressive in use of banding in the last 6-8 months, and particularly lax about removal of banding. Openreach will need to rethink the impact of DLM and banding if dynamic SNRMs are to be useful to those lines.
Standard User adslmax
(knowledge is power) Wed 11-Jan-17 17:43:58
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
DLM has decided to reduced SNR to 6.6 from 12.1 after 392 days connected as it went downtime this morning for a few minute - here is full stats:

Downstream Upstream
Line Coding (Trellis) On On
SNR Margin (dB) 6.0 6.1
Attenuation (dB) 11.3 0.0
Output Power (dBm) 12.5 -1.2
Attainable Rate (Kbps) 83367 21278
Rate (Kbps) 79999 19999

Edited by adslmax (Wed 11-Jan-17 17:44:51)

Standard User adslmax
(knowledge is power) Wed 11-Jan-17 18:39:41
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Or maybe my cabinet is reduced SNR cos of more taken in or due to crosstalk?
Standard User AndyHCZ
(committed) Wed 11-Jan-17 19:11:38
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Openreach will be extending their 'trial' of the variable dB and new DLM algorithm from Monday 16 January to select cabinets on the following exchanges (below).

A few points here though:

- ECI cabinets are excluded (I assume the new DLM is not fully tested/supported yet).
- Any line that has had the existing DLM intervene, due to poor performance, will be excluded from being moved over.
- Around 10% of lines are expected to move to the new XdB and DLM algo.

Ashburton
Ashcott
Ashreigney
Ashwater
Axbridge
Axminster
Baltonsborough
Bampton, Devon
Banwell
Barnstaple
Bath Kingsmead
Batheaston
Beaford
Beaworthy
Beckington
Bere Alston
Bickington
Bickleigh
Bideford
Bigbury-On-Sea
Bishops Lydeard
Bishops Nympton
Black Torrington
Blackawton
Blagdon
Blagdon Hill
Bleadon
Bovey Tracey
Bow
Box
Bradford -On-Avon
Bradford- On-Tone
Bradworthy
Branscombe
Bratton Clovelly
Braunton
Brayford
Brean Down
Brent Knoll
Bridestowe
Bridgerule
Bridgwater
Bristol West
Brixham
Broadhembury
Bruton
Buckfastleigh
Buckland St.Mary
Budleigh Salterton
Burnham-On-Sea
Burrowbridge
Castle Cary
Chagford
Chapmanslade
Chard
Charlton Mackrell
Cheddar
Chelston
Cheriton Bishop
Cheriton Fitzpaine
Chew Magna
Chewton Mendip
Chillaton
Chilton Polden
Chiselborough
Chittlehamholt
Chudleigh
Chulmleigh
Churchill
Churston
Clevedon
Clovelly
Colaton Raleigh
Colyton
Combe Down
Combe Martin
Combwich
Compton Dando
Copplestone
Cornwood
Corscombe
Corton Denham
Craddock
Cranmore
Crediton
Crewkerne
Crowcombe
Crownhill
Croyde
Cullompton
Dartmouth
Dawlish
Devonport
Ditcheat
Dittisham
Dolton
Drewsteignton
Dulverton
Dunster
East Allington
Edingworth
Evercreech
Exbourne
Exeter
Exeter Exminster
Exford
Exmouth
Faulkland
Feniton
Flax Bourton
Frogmore
Frome
Gara Bridge
Glastonbury
Harbertonford
Hartland
Hatch Beauchamp
Hatherleigh
Hawkchurch
Haytor
Hele
Hemyock
Henlade
High Bickington
Holbeton
Holford
Holsworthy
Honiton
Horns Cross
Ilchester
Ilfracombe
Ilminster
Instow
Ipplepen
Isle Brewers
Ivybridge
Kennford
Kentisbeare
Kingsbridge
Kingskerswell
Kingston St Mary
Kingswear
Langport
Langtree
Lapford
Launceston
Lewdown
Lifton
Limpley Stoke
Loddiswell
Long Ashton
Long Sutton, Somerset
Longdown
Lulsgate
Luppitt
Lustleigh
Lydeard St.Lawrence
Lydford
Lyme Regis
Lynton
Maiden Bradley
Manaton
Mark Moor
Marston Magna
Martock
Meare Heath
Mells
Midsomer Norton
Milborne Port
Milverton
Minehead
Modbury
Morchard Bishop
Moretonhampstead
Nailsea
Nether Stowey
Newton Abbot
Newton Ferrers
Newton St.Cyres
Newton Tracey
North Cadbury
North Curry
North Molton
North Petherton
North Tawton
Nunney
Oakford
Oakhill
Okehampton
Ottery St.Mary
Paignton
Pill
Pilton
Pinhoe
Plymouth
Plymstock
Porlock
Portishead
Priddy
Princetown
Puriton
Radstock
Roborough
Salcombe
Saltford
Sampford Peverell
Seaton
Shaldon
Shaugh Prior
Shebbear
Shepton Mallet
Shiphay Collaton
Shirwell
Sidbury
Sidmouth
Silverton
Somerton
South Brent
South Chard
South Molton
South Petherton
Sowton
Spaxton
St. Budeaux
St. Marychurch
Stalbridge
Starcross
Staverton
Stockland
Stogumber
Stoke Canon
Stoke Fleming
Stoke Gabriel
Stratton On The Fosse
Street
Stroud
Sutton Cross
Swimbridge
Taunton
Tavistock
Tedburn St.Mary
Teignmouth
Temple Cloud
Templecombe
Timberscombe
Timsbury
Tiverton
Topsham
Torcross
Torquay
Torrington
Totnes
Trowbridge
Washford
Wedmore
Wellington
Wells
Wembury
West Coker
West Harptree
Weston Super Mare
Weston Zoyland
Whiddon Down
Whimple
Widecombe -In-The-Moor
Williton
Wincanton
Winkleigh
Winscombe
Winsford, Somerset
Witheridge
Wiveliscombe
Woodbury
Woolacombe
Worle
Wrington
Yatton
Yealmpton
Yelverton
Yeovil
Yetminster
Standard User adslmax
(knowledge is power) Wed 11-Jan-17 20:15:01
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
Unbelievable (nothing for Cuckoo Oak) ?
Standard User Chrysalis
(legend) Wed 11-Jan-17 20:19:33
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
I appreciate the information but its a case of "no surprise" with the ECI cabinets as rolling out 3db without g.inp is risky.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User Chrysalis
(legend) Wed 11-Jan-17 20:20:03
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
why do you want 3db? you have a max sync anyway.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User adslmax
(knowledge is power) Wed 11-Jan-17 20:23:07
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
I suppose so! But I start to worrying now because my Sync Rate might reduced pretty soon or later because of Attainable Rate have dropping slighty since 2014. Before used to be 113675k but now at 83367k. The SNR also drop too since 2014. Before use to be at 13.7dB now at 6.0dB.

Edited by adslmax (Wed 11-Jan-17 20:24:18)

Standard User AndyHCZ
(committed) Wed 11-Jan-17 20:55:56
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
You're syncing max rate anyway right? So makes no difference to you...
Standard User WWWombat
(knowledge is power) Wed 11-Jan-17 22:29:04
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
I guess you show that SNR of 7.7dB is equivalent to about 33Mbps.

If you get a target of 3dB, your attainable is likely to increase by 12Mbps - ish.
Standard User Zarjaz
(eat-sleep-adslguide) Thu 12-Jan-17 07:18:00
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
I wonder why the remote system would lower the SNR if the line in question already achieves max sync ?
Surely it would be better to have a little built in stability ?

Standard User lee111s
(experienced) Thu 12-Jan-17 07:42:25
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Zarjaz] [link to this post]
 
Crosstalk is the only reason can think of, in which case the max attainable wouldn't really increase by 12meg or whatever, it would simply allow it to maintain a higher connection rate?
Standard User wolvesmad
(fountain of knowledge) Thu 12-Jan-17 08:12:59
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
No Midlands exchanges on that list by the looks.

-

BT BroadbandInfinity 2
Standard User wolvesmad
(fountain of knowledge) Thu 12-Jan-17 08:15:24
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Looks like crosstalk to me.

Mines gone from 82Mb attainable to 68Mb in 18 months and the cab is pretty much full now.

-

BT BroadbandInfinity 2
Standard User WelshWArrior
(fountain of knowledge) Thu 12-Jan-17 08:16:29
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
Hmmm not 1 Welsh exchange on that list as far as I can see. Wonder why that is? Where do you get this list?

-------------------------------------------
BT Infinity 2 Unlimited
http://www.thinkbroadband.com/speedtest/button/14676...
Standard User Zarjaz
(eat-sleep-adslguide) Thu 12-Jan-17 08:31:02
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WelshWArrior] [link to this post]
 
Don't get too worried, I see none for around this way (SE of England) either.

Standard User WelshWArrior
(fountain of knowledge) Thu 12-Jan-17 08:33:56
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Zarjaz] [link to this post]
 
I'm not that bothered - just thought it was a bit strange that there aren't any Welsh exchanges mentioned at all. I'm happy with my 64Mbps-ish sync @ 6.2db for now.

I wonder what sort of increase I'd get when it does kick in nation-wide??

-------------------------------------------
BT Infinity 2 Unlimited
http://www.thinkbroadband.com/speedtest/button/14676...
Standard User lee111s
(experienced) Thu 12-Jan-17 09:20:39
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WelshWArrior] [link to this post]
 
No North East ones either, I wouldn't worry.

Probably somewhere in the region of 6-12meg extra.
Standard User WelshWArrior
(fountain of knowledge) Thu 12-Jan-17 09:26:23
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
That would be a nice gain. Even at 64Mbps, with BT TV, 2 Laptops and 2 kids on their tablets, my connection is showing hints of starting to struggle wink

-------------------------------------------
BT Infinity 2 Unlimited
http://www.thinkbroadband.com/speedtest/button/14676...
Standard User lee111s
(experienced) Thu 12-Jan-17 09:28:21
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WelshWArrior] [link to this post]
 
Unless you're constatly streaming UHD or downloading large files all of the time, then it really shouldn't be.

64mbps would get you 10 simultaneous HD Iplayer streams.
Standard User aavid60
(regular) Thu 12-Jan-17 09:28:37
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
It looks like the only exchanges to get this update are all down south. is this the north south divide again. None as I can see in the north west
Standard User WelshWArrior
(fountain of knowledge) Thu 12-Jan-17 09:38:59
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
It not that bad really. I do watch some of the UHD content on BT. I think the times it struggles is when BT TV is showing 1 channel and recording 2 more porgrams at same time, coupled with the girls watching youtube on their tablets and the wife doing what she does on her laptop!

Still can't complain - a mate who lives about 500m from me still only gets 0.5Mbps!!

-------------------------------------------
BT Infinity 2 Unlimited
http://www.thinkbroadband.com/speedtest/button/14676...
Standard User MHC
(sensei) Thu 12-Jan-17 09:46:48
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
I'll comment here rather than on several other posts that are complaining about North/South diviude, no exchanges in Wales, nothing in NE, none is SE ...

All of the exchanges appear to be those located in just one region - South West England, Somerset, Devon, Cornwall and may be Wiltshire. That seems to be a sensible choice rather than dotted around all over the UK.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User AndyHCZ
(committed) Thu 12-Jan-17 09:57:48
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MHC] [link to this post]
 
I believe it's all in Devon and Somerset.
Standard User MHC
(sensei) Thu 12-Jan-17 10:10:19
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
Trowbridge is Wiltshire, Bristol West is ??? I thought I had seen one or two in Cornwall but without getting an atlas. The pint is still valid that they are in just one defined geographic area


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User AndyHCZ
(committed) Thu 12-Jan-17 10:17:14
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MHC] [link to this post]
 
Actually you're right. Main concentration does seem to be Devon and Somerset with some bordering areas in other counties included.
Standard User Nightglow
(member) Thu 12-Jan-17 11:14:36
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MHC] [link to this post]
 
And Chapmanslade is also in Wiltshire, yet they miss Warminster & Westbury both are only 3 miles from the village.

Edited by Nightglow (Thu 12-Jan-17 11:15:22)

Standard User MHC
(sensei) Thu 12-Jan-17 11:22:16
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
There will be good reason and a boundary needs to be drawn ...

Maybe it is based on where the main fibre connections and hubs are ... Perhaps Chapmansbury goes to Frome in Somerset whereas the others could be linked to somewhere like Salisbury.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User awontroba
(regular) Thu 12-Jan-17 11:41:12
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
My FTTC connection at my mother's is on one of the affected exchanges. It was one of the first to be enabled on the cabinet in May. Between mid June and October I lost 12 Mbps. I wonder what will happen after 16/01.

TBB speed tests
Wed 11/01/17 21:15	55.13 Mbps	57.67 Mbps	18.60 Mbps
Wed 11/01/17 04:55	58.23 Mbps	58.12 Mbps	18.61 Mbps
Thu 22/12/16 23:23	58.18 Mbps	57.77 Mbps	18.62 Mbps
Fri 04/11/16 06:25	57.83 Mbps	57.69 Mbps	18.59 Mbps
Sun 30/10/16 14:22	57.85 Mbps	57.59 Mbps	18.57 Mbps
Fri 17/06/16 04:44	69.93 Mbps	69.95 Mbps	18.43 Mbps
Sun 12/06/16 23:29	69.92 Mbps	69.63 Mbps	18.59 Mbps
Sun 12/06/16 03:12	69.81 Mbps	69.87 Mbps	18.60 Mbps
Tue 31/05/16 17:17	67.04 Mbps	66.65 Mbps	18.59 Mbps
Sun 29/05/16 23:03	49.36 Mbps	73.47 Mbps	18.64 Mbps
Thu 26/05/16 02:50	74.04 Mbps	73.85 Mbps	18.61 Mbps
Mon 23/05/16 17:11	74.10 Mbps	44.76 Mbps	17.73 Mbps


BT HH5 Troubleshooting extract

1.	Product Name:	HomeHub5
3.	Firmware version:	v0.07.06.09028-BT (Type B) Last updated 3/11/2016
4.	Board version:	01
5.	VDSL uptime:	4 days, 16:11:10
6.	Data Rate:	19999 / 62582
7.	Maximum Data Rate:	22937 / 62491
8.	Noise Margin:	7.6 / 6.0
9.	Line Attenuation:	22.5 / 18.1


--
Adrian
Standard User MHC
(sensei) Thu 12-Jan-17 11:52:29
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: awontroba] [link to this post]
 
No one, apart from those in BT, knows what the parameters are to switch from a 6dB to 3dB profile or back. It could look at up time, error rates, total errors, SNR variation over 24/48 hours, how close you are to your service speed (80/55/40/15), have you have 3dB before and DLM reverted you to 6dB and probably a combination of factors.

It will be a case of wait and see.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User choppersrock
(learned) Thu 12-Jan-17 14:41:12
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
I live in Frome, we are on the list but 99% of Frome is on ECI which according to the post over on kitz is excluded frown

Sky Fibre Pro - Zyxel vmg8324 (v14 bridge mode) + PFSENSE 2.4.0 with ipv6 - ECI cab, G.INP disabled as of 8th April 2016

http://www.mydslwebstats.co.uk user upload ID skyECI
Standard User adslmax
(knowledge is power) Thu 12-Jan-17 16:04:38
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: wolvesmad] [link to this post]
 
In reply to a post by wolvesmad:
No Midlands exchanges on that list by the looks.


There is one! Wellington, Telford, West Midlands
Standard User MHC
(sensei) Thu 12-Jan-17 16:12:27
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
In reply to a post by adslmax:
In reply to a post by wolvesmad:
No Midlands exchanges on that list by the looks.


There is one! Wellington, Telford, West Midlands



WRONG

That is most likely to be Wellington in Somerset


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User choppersrock
(learned) Thu 12-Jan-17 17:40:44
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MHC] [link to this post]
 
Well I hope g.inp gets resolved in the spring on my eci cab then I might see the lower snr at some point here in Frome..

Sky Fibre Pro - Zyxel vmg8324 (v14 bridge mode) + PFSENSE 2.4.0 with ipv6 - ECI cab, G.INP disabled as of 8th April 2016

http://www.mydslwebstats.co.uk user upload ID skyECI

Edited by choppersrock (Thu 12-Jan-17 17:41:28)

Standard User WWWombat
(knowledge is power) Thu 12-Jan-17 19:33:03
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Zarjaz] [link to this post]
 
In reply to a post by Zarjaz:
I wonder why the remote system would lower the SNR if the line in question already achieves max sync ?
Surely it would be better to have a little built in stability ?


The O&M system might reduce the target SNRM, but if the actual sync is already at the maximum then it wouldn't / couldn't reduce the actual SNRM to be less than the current 6dB.

Of course, if takeup slowly increases the crosstalk, that max attainable is going to come down anyway...
Standard User WWWombat
(knowledge is power) Thu 12-Jan-17 19:35:45
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MHC] [link to this post]
 
In reply to a post by MHC:
There will be good reason and a boundary needs to be drawn ...


I just saw that BT are behind on getting to their phase 1 target in CDS - by around 10,000 premises.

Perhaps this just helps them bring a few more subscribers into SFBB range.

As it is a BDUK thing, then the intervention area has likely been done by Huawei cabinets anyway.
Standard User Icaras
(experienced) Fri 13-Jan-17 07:07:18
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: smallal] [link to this post]
 
In reply to a post by smallal:
Chatting to a Kellys engineer he told me the strategy for the 3db profile is so BT can offer a speed boost for infinity 2 customers following the upgrade to infinity 1. Scuttlebutt is it will be up to 100mb, which also means offering a speed directly comparable to Virgins package.


Now how the hell would a Kelly's employee know anything about BT strategy? Ignore him.
Standard User Nightglow
(member) Fri 13-Jan-17 10:01:19
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
In reply to a post by Icaras:
In reply to a post by smallal:
Chatting to a Kellys engineer he told me the strategy for the 3db profile is so BT can offer a speed boost for infinity 2 customers following the upgrade to infinity 1. Scuttlebutt is it will be up to 100mb, which also means offering a speed directly comparable to Virgins package.


Now how the hell would a Kelly's employee know anything about BT strategy? Ignore him.



Wait & seewink

Edited by Nightglow (Fri 13-Jan-17 10:01:48)

Administrator MrSaffron
(staff) Fri 13-Jan-17 10:15:31
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Given a few more hours in a day will be able to create a special group for the postcodes believed to be involved, and can then do comparisons for FTTC speeds compared to say 12 months ago

On the CDS scenario, don't know the exact number of premises in contract paperwork as was signed, but in terms of delivery the fighting is going to be about the drop from VDSL2 coverage, to 24 Mbps or 30 Mbps thresholds. In what has been delivered 84% can get over 24 Mbps and a lower 81.8% on our figures. That said there is some FTTP still in build, and there has been some infill work. Will do an overall CDS report at weekend, as the commercial areas have an impact on the 90% target too.

What I will say is I am expecting CDS to fight tooth and nail over even a slight delay even if this just down to extra time needed for FTTP work. The journey so far has not been a friendly one.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User Westyfield2
(newbie) Fri 13-Jan-17 13:19:35
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
Interesting to see my Exchange listed in this.

I was the first to get FTTC when my cabinet was done:.
- Speedtest: 55Mb/s download and 17Mb/s upload
- IP Profile: 57.1Mb/s download and 20Mb/s upload.

After a few weeks
- Speedtest: 52Mb/s download
- IP Profile: 53.89Mb/s download
When ordering the speed estimate given by BT was 51.5Mb/s so still pretty much spot on.

Then on 3/10/2013 my neighbour got FTTC and gave me a big hit. In one day:
- IP Profile: 36.7Mb/s

Got a friendly OpenReach engineer to do me a DLM reset on 5/10/2013
- Speedtest: 39.3Mb/s
- IP Profile: 40.7Mb/s

ISP sent an OpenReach engineer round, but they weren’t much help. Basically all they kept saying was “tester says the line is running at 100%”, had no answer when I pointed out that it was 13Mb/s faster before, and didn’t have a clue what crosstalk was when I mentioned it.


Wind on 3 years to today, and the rollout of G.INP and so on have given me a slight gain. Now:
- Speedtest: 45.6Mb/s download and 11.5Mb/s upload

Also over the duration BT revised down the Wholesale checker results. It now lists
- Clean: 62.8-46.4Mb/s download and 18.5-12.54Mb/s upload
- Impacted: 47.4-25.5Mb/s download and 15.2-6.94Mb/s upload.

Will be intrigued to see what the lower target SNRm will do. Doesn’t seem that long ago we were able to set it ourselves with BeThere and the tweaking on the modem/routers!
Standard User Icaras
(experienced) Fri 13-Jan-17 17:02:20
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Westyfield2] [link to this post]
 
I don't think there's any training on crosstalk. I don't remember any.

So as you'll appreciate some engineers will know about it but many won't. Maybe there's no training because there's nothing an engineer can do about it?
Standard User Chrysalis
(legend) Fri 13-Jan-17 17:57:20
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
an engineer can do something about, its called a pair swap wink
they could also replace bundles with less densily populated bundles to reduce likelyhood and extremity of crosstalk.

Of course these things take up time and money so they like people to think nothing can be done about it. smile

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User MCM
(knowledge is power) Fri 13-Jan-17 18:37:45
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
Of course these things take up time and money
And there's the rub. Money for improvement is in short supply given that the vast majority of users seem hellbent on paying as little as they possibly can for broadband access with large numbers gravitating towards the cheapest supplier that they can find.

BT OR & perhaps also VM might be able to improve their respective systems if they charged more however this would be considered unacceptable by many especially so those ISPs who seem to feel that BT OR should be supplying first class connectivity, preferably FTTP, for next to nothing regardless of the cost to BT which like the ISPs is essentially a private company rather than a charity.
Administrator MrSaffron
(staff) Fri 13-Jan-17 18:40:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
A pair swap would be a trial and error thing, and no way of knowing if in another week another user goes live in the bundle and gives you even worse cross talk.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User Chrysalis
(legend) Fri 13-Jan-17 19:37:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
true, but its still not the same as stating they powerless.

a guy on kitz after the openreach exec team got involved had a speed issue resolved, when management approve it suddenly they can get things done.

They redug a trench, fed some new cable through and swapped his port at the cabinet all in a single day.

Normal support channels got him nowhere.

His experience has shown what can happen when the CP is taken out of the equation and we deal with openreach direct.

Without CPs been in the middle openreach also can take a larger revenue as the CP middle man mark up is removed from the relationship as well.

I see CPs been involved in the line retal arrangement as akin to a letting agent renting out properties, they are a useless leech.

Sky Fibre Pro BQM - IPv4 BQM - IPv6

Edited by Chrysalis (Fri 13-Jan-17 19:43:25)

Standard User MCM
(knowledge is power) Fri 13-Jan-17 19:59:08
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
I see CPs been involved in the line rental arrangement as akin to a letting agent renting out properties, they are a useless leech.
I and suspect many others wholeheartedly agree with your statement.
Standard User Zarjaz
(eat-sleep-adslguide) Fri 13-Jan-17 20:50:55
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
Completely agree Mr.S.

Standard User Zarjaz
(eat-sleep-adslguide) Fri 13-Jan-17 20:58:01
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MCM] [link to this post]
 
Hear hear.

Standard User AndyHCZ
(committed) Fri 13-Jan-17 21:02:47
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
How much do you think this issue cost to resolve?
Standard User Chrysalis
(legend) Fri 13-Jan-17 21:44:24
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
the wages of 2 men 6 hours work.

I dont know what equipment was used to do the digging.

How is that relevant to if something is possible or not?

If something isnt done due to it been deemed too expensive that is not the same as something been not possible.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User Chrysalis
(legend) Fri 13-Jan-17 21:50:07
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MCM] [link to this post]
 
of course you only referring to CPs not end users, as CPs are openreach customers.

CPs can quite easily misjudge what is what.

Just because CPs agree silly arrangements like only accepting a minimum sin test been carried out on a line to see if its voice capable, it doesnt mean end users would agree to such nonsense.

e.g. in my own case I have paid circa £960 in line rental that has been passed onto openreach at this address, all the callouts that have occured since then have probably not reached that figure in costs to openreach.

Not to mention the number of properties where line rental is paid and there is no callouts whatsoever, line rental is like the insurance business, some customers will not be profitable but the majority will be and that subsidises those who are not.

I am surprised some are trying to defend this openreach and middleman CP arrangement and the current service levels in place. Even openreach themselves have said its not satisfactory.

Sky Fibre Pro BQM - IPv4 BQM - IPv6

Edited by Chrysalis (Fri 13-Jan-17 21:54:41)

Standard User Chrysalis
(legend) Fri 13-Jan-17 21:55:20
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MCM] [link to this post]
 
not everyone judging by the replies smile

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User AndyHCZ
(committed) Fri 13-Jan-17 22:19:56
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
It's possibly to replace every piece of copper cable in the country, it's neither practical nor is it cost effective to do so.

It looks to me that OR did a special favour to resolve that line issue, which wasn't part of their normal protocol.
Standard User Ignitionnet
(knowledge is power) Fri 13-Jan-17 23:57:59
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
In reply to a post by adslmax:
Or maybe my cabinet is reduced SNR cos of more taken in or due to crosstalk?


This.
Standard User Chrysalis
(legend) Sat 14-Jan-17 01:00:54
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
I never said it was cost effective, I just said its possible. I also never suggested they should be replacing all of the copper nationwide,

Of course tho without CPs been in the way leeching of revenue and with openreach able to increase prices to compensate for lack of CP profit margin, openreach would also have more headroom to do better fixes on their network.

Generally tho replacing copper is dumb anyway as its not future proof. But thats the path openreach have chosen.

Sky Fibre Pro BQM - IPv4 BQM - IPv6

Edited by Chrysalis (Sat 14-Jan-17 01:01:39)

Standard User billford
(elder) Sat 14-Jan-17 01:10:50
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
In reply to a post by Chrysalis:
Generally tho replacing copper is dumb anyway as its not future proof. But thats the path openreach have chosen.
The only thing that is truly future-proof is a reliable crystal ball and a bottomless pit of money... companies do what they can with what's available.




edit- typo

Bill
A level playing field is level in both directions.

_______________________________________Planes and Boats and ... ______________BQMs: IPv4 IPv6

Edited by billford (Sat 14-Jan-17 01:12:02)

Standard User WWWombat
(knowledge is power) Sat 14-Jan-17 02:34:17
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
What I will say is I am expecting CDS to fight tooth and nail ... The journey so far has not been a friendly one.


That's *really* obvious.

In the recent meeting, one Devon councillor was ripping into BT for having not installed many of the vouchers from the recent voucher scheme. Once it was pointed out that BT wasn't involved, the vitriol went, and he listened to the (reasonable) explanation.

In reply to a post by MrSaffron:
... over even a slight delay even if this just down to extra time needed for FTTP work.


The last meeting suggested the delays were mostly related to wayleaves, and are likely to be sorted in the first 3 months of the year.

If I have the numbers right, the delays affect around 4% of the total premises due to get SF speeds. That makes the delay/numbers very similar to those encountered by North Yorkshire. That delay didn't cause any particular fractiousness, but did allow the council to apply a little leverage to encourage completion of 3 "at risk" commercial cabinets.

In terms of outcome, it seems that CDS is getting a similar result to the rest of the country. A project complete almost on time, and certainly within budget. But the experience on the journey ...

In reply to a post by MrSaffron:
Given a few more hours in a day


Funny how Santa never brings *that* present...

In reply to a post by MrSaffron:
On the CDS scenario, don't know the exact number of premises in contract paperwork as was signed, but in terms of delivery the fighting is going to be about the drop from VDSL2 coverage, to 24 Mbps or 30 Mbps thresholds. In what has been delivered 84% can get over 24 Mbps and a lower 81.8% on our figures.


I agree where the fight will happen.

From previous work, I figure that 3dB can be worth as much as 11Mbps for people capable of getting 60-80Mbps (because they have all tones available). For lines with speeds around 20-30Mbps, 3dB is likely to give them something in the region of 3 or 6Mbps. The gain at the lower end when they only get the D1 band, the higher gain if they get D1 and a good chunk of D2.

Using your coverage figures (in the fibre guide) around distances of 900-1200m, it seems those speed increases could equate to extra range of 150-300 metres, and extra coverage of 3-5%.

Those numbers could be critical.

In reply to a post by MrSaffron:
That said there is some FTTP still in build, and there has been some infill work. Will do an overall CDS report at weekend, as the commercial areas have an impact on the 90% target too.

That was another aspect noted: that there was outstanding commercial work that means they won't hit 90% even when phase 1 completes.
Standard User WWWombat
(knowledge is power) Sat 14-Jan-17 02:43:20
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
In reply to a post by Nightglow:
In reply to a post by Icaras:
Now how the hell would a Kelly's employee know anything about BT strategy? Ignore him.

Wait & seewink


It was notable that, even when BT were planning to deploy vectoring, they still weren't planning on increasing the top speed to 100Mbps.

And vectoring would likely have get a bigger gain than a 3dB profile.

An increase in VDSL2 top speed /now/ will reduce the market for G.Fast upgrades (to the 160Mbps level).
Standard User PaulKirby
(knowledge is power) Sat 14-Jan-17 06:23:57
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
In reply to a post by Chrysalis:
true, but its still not the same as stating they powerless.

a guy on kitz after the openreach exec team got involved had a speed issue resolved, when management approve it suddenly they can get things done.

They redug a trench, fed some new cable through and swapped his port at the cabinet all in a single day.

Normal support channels got him nowhere.

His experience has shown what can happen when the CP is taken out of the equation and we deal with openreach direct.

Without CPs been in the middle openreach also can take a larger revenue as the CP middle man mark up is removed from the relationship as well.

I see CPs been involved in the line retal arrangement as akin to a letting agent renting out properties, they are a useless leech.

Well my local MP and myself was getting no where for the last 2 to 5 years with BT's Exec team via emails or over the phone.

We only got our fibre installed when I wrote a polite email to the CEO of BT Group and the Chairman's Office of BT also including a copy of the email that I had just sent my local MP along with evidence etc.

And then a few days later they did some more work down my road then re-booked the engineers and our fibre was installed.

So in my eyes you have to get the people at the top aware of the issues before anything will get done and I think it shouldn't be that way.

Paul

BTBroadband - Infinity 4 - 310Mbps (down), 31Mbps (up)
TBB Speedtest
Standard User Nightglow
(member) Sat 14-Jan-17 10:17:55
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: PaulKirby] [link to this post]
 
In reply to a post by PaulKirby:
In reply to a post by Chrysalis:
true, but its still not the same as stating they powerless.

a guy on kitz after the openreach exec team got involved had a speed issue resolved, when management approve it suddenly they can get things done.

They redug a trench, fed some new cable through and swapped his port at the cabinet all in a single day.

Normal support channels got him nowhere.

His experience has shown what can happen when the CP is taken out of the equation and we deal with openreach direct.

Without CPs been in the middle openreach also can take a larger revenue as the CP middle man mark up is removed from the relationship as well.

I see CPs been involved in the line retal arrangement as akin to a letting agent renting out properties, they are a useless leech.

Well my local MP and myself was getting no where for the last 2 to 5 years with BT's Exec team via emails or over the phone.

We only got our fibre installed when I wrote a polite email to the CEO of BT Group and the Chairman's Office of BT also including a copy of the email that I had just sent my local MP along with evidence etc.

And then a few days later they did some more work down my road then re-booked the engineers and our fibre was installed.

So in my eyes you have to get the people at the top aware of the issues before anything will get done and I think it shouldn't be that way.

Paul


Exactly the same situation, getting 9-14Mb here, despite checker say 70Mb minimum,& contining drop connection, nearly 18 months of getting nowhere with BT/OR at normal levels.
Made myself unpopular by writing to CEO's of BT & OR, with a fortnight, 2 engineers turned up & moved me to the rear pole ran new cable from house & down back lane, had a other few problems,so whole job took them two & half days to sort.

What is so annoying is the number of engineers, think it was eight sent previously to sort problem at various times, one wanted to do something, yet some bean counter wouldn't authorise it, so the problem continue,it shouldn't be like this,the OR engineer on the ground should be allow more freedom to sort the the problem.

Edited by Nightglow (Sat 14-Jan-17 10:26:41)

Administrator MrSaffron
(staff) Sat 14-Jan-17 10:41:17
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Have found the phase I target figure 277,000 at over 24 Mbps, in terms of 'fibre' based well past that point, so distance performance is key here, and the pessimism of our model means we are likely to under shoot BT Group figures. Got one more process running to collate intervention area data.

We have looked at our model versus reality from speed tests and they line up, but scope for a small improvement around the 1km mark, but want to do a deeper split to look at difference per cabinet manufacturer etc. Hope is that in time might be able to see difference vectoring makes, and run multiple models depending on the cabinet type. Too few premises involved in LR-VDSL trials to get anything useful from that trial.

Another factor meaning 90% is hard, is while new build numbers are small, it has a bit of an effect especially if not all of them get VDSL2/FTTP

The tracking of Airband coverage is a challenge, and need to see speed data to see what we call it speed wise. We do see some really great fixed wireless services, but also see some mediocre ones that tick a superfast box but rare to see someone on that product. Can't imagine the outcry if the most popular BT Infinity product was an up to 15 Mbps service.

At end of the day this is looking like a case of very close to targets, and will be able to add my if you want to ensure 100% coverage, best to plan to deliver 110%. The reality of the project target NOT being 90% in each community/constituency/district council area is something I think lots of councillors/MPs are starting to only just understand.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User adslmax
(knowledge is power) Sat 14-Jan-17 11:29:00
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Ignitionnet] [link to this post]
 
In reply to a post by Ignitionnet:
In reply to a post by adslmax:
Or maybe my cabinet is reduced SNR cos of more taken in or due to crosstalk?


This.


What is the precent take up in my cabinet now? How to find out? Maybe Ribble or Andy HCZ will know.

Edited by adslmax (Sat 14-Jan-17 11:30:13)

Standard User WWWombat
(knowledge is power) Sat 14-Jan-17 12:51:18
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
In reply to a post by adslmax:
What is the precent take up in my cabinet now?


Why? It doesn't matter anywhere near as much as knowing how many of the 10-12 pairs that are neighbours to your pair through the full length of the D-side.
Standard User WWWombat
(knowledge is power) Sat 14-Jan-17 13:10:51
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
Have found the phase I target figure 277,000 at over 24 Mbps,

I agree.

Looking forward to the data coming out...

In reply to a post by MrSaffron:
but scope for a small improvement around the 1km mark,

Dang. Just at the important point...

In reply to a post by MrSaffron:
Can't imagine the outcry if the most popular BT Infinity product was an up to 15 Mbps service.

Like Australia? For a year, the 12/1 product was the most popular to FTTP subscribers.

Even now, the 12/1 and 25/5 products combine to take 80% of the market on FTTP and 90% of FTTN (which is an "up to 100" vectored variety).

NBN Package Mix - FTTP
NBN Package Mix - FTTN
In reply to a post by MrSaffron:
if you want to ensure 100% coverage, best to plan to deliver 110%.

I agree 110% wink

In reply to a post by MrSaffron:
The reality of the project target NOT being 90% in each community/constituency/district council area is something I think lots of councillors/MPs are starting to only just understand.


I wonder what we'll see going forward. Will Gigaclear stick to a 95% target, so only hit half of the remainder? How much rein will they be given by councillors?
Administrator MrSaffron
(staff) Sat 14-Jan-17 13:20:53
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Gigaclear contract is 35,000 premises so a long way from getting to 100%, and short of 95% too, but Airband and the outstanding lot likely to take it to 95%, if BT get to 90%.

http://www.thinkbroadband.com/news/7611-connecting-d...

The analysis, believe BT is 20,000 short based on our understanding of what has been delivered, so will be interesting to see how much closer it gets by March. Even if BT stopped now would just a 7% miss on original target, so while a miss compared to many procurement exercises not massive, but can see FTTP areas with postcodes not live where checkers say they are building to, while others are giving us speed test results in live postcodes.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User adslmax
(knowledge is power) Sat 14-Jan-17 13:23:56
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
If my cabinet is 100% take up full, does it mean my sync rate 79999k will drop below for the first time since Feb 2014 and how far will it drop to? I hope it won't drop below 79999k when the cab is full?

Edited by adslmax (Sat 14-Jan-17 13:25:48)

Administrator MrSaffron
(staff) Sat 14-Jan-17 13:30:45
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
No one can tell you until someone does the mathematics and knows all the detail on where in the cable bundles your line is with relation to the other people who have ordered the service.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User WWWombat
(knowledge is power) Sat 14-Jan-17 13:38:46
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
It doesn't matter how full the cab is.

It matters more about whether the 10-12 copper pairs surrounding yours have taken VDSL2 service or not.

That means you can get close to the worst-case crosstalk from just 10-12 other subscribers.

Or, if the other 287 FTTC subscribers are on other D-side cables you can end up with nearly (*) no crosstalk at all.

Even when the disturbers are in the worst possible placement, it still depends on the manufacturing quality of the cable: just how uniform is the thickness of copper, the thickness of insulation, the twist rate of a pair and the twist rate of the individual binders.

It is, to all intents and purposes, random. It is likely that you will experience more crosstalk on a full cab ... but there is no guarantee as to whether you experience nearer the minimum or maximum.

(*) - The tie pairs guarantee that you have crosstalk from some VDSL2 subscribers for a short length. The extent of the impact will depend on takeup (**) and the distance between the two cabinets.

(**) - Once the binder in the tie pair (group of 25 pairs) is full, you'll likely have gotten most of the crosstalk from this short portion of your line; once the tie-pair cable is full (100 pairs), that likelihood will reach 100%.
Standard User adslmax
(knowledge is power) Sat 14-Jan-17 13:47:08
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Why can't BT Wholesale Broadband Diagnostic Test or Availability Checker to show how many % of the lines take up of the cabinet?
Standard User lee111s
(experienced) Sat 14-Jan-17 13:53:59
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
It's not relevant to anyone.

Also, Wholesale are not the owner of the cabinets, Openreach are.
Standard User RobertoS
(elder) Sat 14-Jan-17 17:20:26
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
In reply to a post by adslmax:
Why can't BT Wholesale Broadband Diagnostic Test or Availability Checker to show how many % of the lines take up of the cabinet?
Several years ago Openreach or BTW used to publish to ISPs the DSLAM and MSAN numbers, card occupancy in them and ports used at all exchanges for ADSL. It was available to the public through Prodigynet - or at least to their customers.

As were the complete order history and current orders for your line.

They got stopped from letting us see that data.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WWWombat
(knowledge is power) Sat 14-Jan-17 21:42:18
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
In reply to a post by adslmax:
Why can't BT Wholesale Broadband Diagnostic Test or Availability Checker to show how many % of the lines take up of the cabinet?


As the others said, it's useless to you.

But also because, quite frankly, it would be extraordinarily useful market intelligence data for all of their competitors.
Standard User ukhardy07
(knowledge is power) Sat 14-Jan-17 23:49:55
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Zarjaz] [link to this post]
 
In reply to a post by Zarjaz:
I wonder why the remote system would lower the SNR if the line in question already achieves max sync ?
Surely it would be better to have a little built in stability ?
Not sure how fibre works but if we look at sky ADSL, there is a power management module used to reduce output power which lowers the noise margin, reduces DSLAM energy and thereby lower costs.

Here's the one sky uses as far as I know:

http://www.assia-inc.com/products-services/pdf/Brief...

Savings equate to around 3KWh per line which is 30 to 50p a year per customer, multiplied by several million customers, you have your answer.

Edited by ukhardy07 (Sat 14-Jan-17 23:53:32)

Standard User WWWombat
(knowledge is power) Sun 15-Jan-17 00:31:16
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: ukhardy07] [link to this post]
 
BT uses their own home-brew DLM equivalent to Assia's.

Lowering the power will reduce the received signal strength, so reduce the SNR. That will tend to reduce the sync speed.

If you want to maintain speed, then you can only reduce the transmit power on those lines already syncing at full speed. That might be 20% of lines at 80Mbps, or 30% of lines at 40-55Mbps.

However, crosstalk can cut in at any point, as new subscribers join. If you are on a reduced power, and they reduce your working SNRM you will need to increase power to get back your error-free margins. And other neighbouring lines will do the same.

As each of you increase your power, you'll start interfering with all your neighbouring lines a little more ... so they all have to react.

It can be a vicious circle...
Standard User Chrysalis
(legend) Sun 15-Jan-17 21:06:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
I have always wondered if DLM cuts power on lines with excessive snrm, user thinks its crosstalk, then if the sync falls below max power is never increased again.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User WWWombat
(knowledge is power) Mon 16-Jan-17 14:35:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
You could be right, but that would make DLM rather dumb. Unfortunately, as time goes by, DLM seems to elevate its dumbness.

One problem I have with "power" is that it is a tricky concept to deal with, and one that many people (including me) cannot handle properly.

For example, we are very used to seeing the idea that profile 17a is listed with a maximum power of 14.5dBm, and seeing modems report power - anywhere from -10dBm to 13+dBm.

But those numbers are aggregate power, accumulated from the individual power on each tone. And there is another limitation that affects the individual power on tones: the PSD (power spectral density), measured in dBm per Hertz.

So, when we see a modem report a lower-than-expected (aggregate) power value, it might be because
- there are fewer tones than expected
- the PSD mask has limited power of many tones
- "something" has reduced the power of individual tones (eg UPBO or DPBO). (*)

There's also the gotcha that we're counting in log scales. Doubling power is +3dBm. Or, when calculating aggregate power, doubling the number of tones at the same power is also +3dBm.

LR-VDSL has a change that allows aggregate power to be +20.5dBm instead of 14.5dBm. A 6dBm difference means quadruple power ... but aggregated over (roughly) only half as many tones ... so could mean octuple power per tone. Wow.

Except it has to fit inside the broad parameters of the existing PSD mask (power per hertz), but benefitting from removal of the DPBO shaping that would otherwise allow coexistence with ADSL.

Who can tell, off the top of their heads, whether +6dBm in aggregate amounts to more or less than the change in shape of the PSD mask?



(*) - The UPBO article is interesting. It shows that the settings can be tuned to a "preferred distance", above which the upstream speeds fall away considerably.
Standard User RobertoS
(elder) Mon 16-Jan-17 14:50:25
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
In reply to a post by WWWombat:
You could be right, but that would make DLM rather dumb. Unfortunately, as time goes by, DLM seems to elevate its dumbness.
I believe there is also a form of "conflict of interest" on the specification of requirements from Openreach DLM.

The idea of a lower default margin, or simply its availability as happened with the ADSLx BT Wholesale one, is a great idea for most customers at little cost to Openreach. Also conferring on "BT" the bonus of higher average rates to put against Virgin Media.

The conflict comes in that it has been clear from the early days that the BT Wholesale estimate table for any given line, which has to be culled from the Openreach one for VDSL2, has aggressively revised downwards as soon as actuals fall. Again we know the BTW ADSLx ones always tracked actual over time, but the underlying emphasis seems to have changed for VDSL2.

The BT Wholesale and probably the Openreach attitude now seems to be strongly on holding that lines can degrade for a number of reasons, so they aren't going to spend money sorting out even significant degradation.

It's a "Shrug the shoulders - that's what happens" sort of approach. "The user still has a service so what the heck?"

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6

Edited by RobertoS (Mon 16-Jan-17 14:51:16)

Standard User philippercival
(knowledge is power) Mon 16-Jan-17 17:12:14
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
The BT Wholesale and probably the Openreach attitude now seems to be strongly on holding that lines can degrade for a number of reasons, so they aren't going to spend money sorting out even significant degradation.

It's a "Shrug the shoulders - that's what happens" sort of approach. "The user still has a service so what the heck?"


Agreed, though I have no proof, other than various ISPs telling me that if they report a fault BT will do nothing as it is still above the acceptable level.

BT will have to be a little careful in the future though I suspect. Many countries are switching to their mobile phone networks and I am very impressed with what 4G can do ( though admittedly not where I currently live). I know a lot of people in the UK have already given up their land lines and as 4G becomes more widely available I suspect this will accelerate. Unfortunately thanks to Plusnet switching it off I can not see my recent usage, but if I was to take all the money I pay for phone and broadband, that would buy me a fair whack from a mobile network.

Standard User AndyHCZ
(committed) Mon 16-Jan-17 17:23:33
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: philippercival] [link to this post]
 
There has to be some threshold for fault investigation though.

I've seen some people (with low cost ISPs) requesting an engineer just because their sync rate has dropped from 80Mbps to 75Mbps.
Standard User adslmax
(knowledge is power) Mon 16-Jan-17 17:35:21
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
In reply to a post by AndyHCZ:
There has to be some threshold for fault investigation though.

I've seen some people (with low cost ISPs) requesting an engineer just because their sync rate has dropped from 80Mbps to 75Mbps.


I probably do the same if my sync rate has dropped to below 74999k from 79999k to ask my isp to get engineer out to reset DLM.
Standard User AndyHCZ
(committed) Mon 16-Jan-17 17:36:05
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
And that is one of the reasons why we have a fault threshold.
Standard User WWWombat
(knowledge is power) Mon 16-Jan-17 19:12:01
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
What do you get them to do if it wasn't caused by DLM?
Standard User WWWombat
(knowledge is power) Mon 16-Jan-17 19:17:09
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
It's a "Shrug the shoulders - that's what happens" sort of approach. "The user still has a service so what the heck?"


To use an Americanism, its all about stopping the truck rolls. Whatever approach is used in the field, the aim is to be able to shrug the shoulders apart from a limited, manageable, number of lines. We just need BT to pick an approach that works for us as well as them.

Vectoring, for example, would have been an approach that lets them shrug shoulders, but would probably have happier subs.
Standard User Chrysalis
(legend) Mon 16-Jan-17 21:00:33
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
nice timing from rev, its as if he read my post O_o

https://www.youtube.com/watch?v=YFdZcEx8oog

Obviously there needs to be some kind of triage or procedure to put in place to keep things in check, but the current system of only checking for voice compliance is clearly not fit for purpose.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User Icaras
(experienced) Tue 17-Jan-17 10:50:38
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
In reply to a post by Chrysalis:
nice timing from rev, its as if he read my post O_o

https://www.youtube.com/watch?v=YFdZcEx8oog

Obviously there needs to be some kind of triage or procedure to put in place to keep things in check, but the current system of only checking for voice compliance is clearly not fit for purpose.


Yes but when an engineer goes out on an SFI job one of the tests they are required to do is an ADSL test on their handheld tester. This checks for errors and has a threshold, over which the test will be classed as a fail. So this notion that the engineer just goes out and only runs a Pair Quality Test (to check for SIN349) is incorrect.
Standard User Chrysalis
(legend) Tue 17-Jan-17 11:06:24
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
They rarely do more then a SIN test when visiting me. In and out in about 10 mins.

The only time's I have had more done is if there is a really big obvious problem with the line that they cannot pretend is not an issue or when I was a customer of aaisp and shaun typically ripped into BTw to ensure stuff got done. smile

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User RobertoS
(elder) Tue 17-Jan-17 11:34:10
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
What do you mean by an ADSL test please? There's a huge difference between the ADSL capability of a line and ADSL2/2+/VDSL2 requirements. I'm assuming the 28kbps requirement is dead, or is it?

We also used to get reports of an ADSL test fail simply meant the line was declared unfit for ADSL, permanently, after being used satisfactorily for years.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User Nightglow
(member) Tue 17-Jan-17 11:44:46
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Has the 3dB rollout taken place, my exchange Kingsmead was listed, but no improvement/increase here with speed.
Standard User AndyHCZ
(committed) Tue 17-Jan-17 11:50:57
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
This was a SFI visit and if so, which modules did the ISP book?
Standard User Icaras
(experienced) Tue 17-Jan-17 11:51:18
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
It's just a test on the handheld tester. It connects to the ADSL for 4 minutes and checks for PPP session, sync speed and CRC, FEC issues etc. This then gets submitted when the job is closed down. It's mandatory and is one of the tests that the engineers are marked and graded on for SFI jobs.

There's also a completely different type of job where the engineer goes to the house, checks line meets SIN349, upgrades the socket if required and then listens for noise on the line. That's a different job type and isn't an SFI task. The CP can order whichever is appropriate, I assume.

Edited by Icaras (Tue 17-Jan-17 11:55:48)

Standard User WWWombat
(knowledge is power) Tue 17-Jan-17 12:10:50
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
Is the qualitative part of the test restricted to error rates?

Is there nothing that checks other signs of a dodgy line, or dodgy connection?
For example
- non standard patterns on hlog
- high noise from neighbours on QLN
- nasty variations to SNRM
- jumps in attenuation
- bad speed mismatch with attenuation
- throughput matching the sync speed
- packet loss
- latency
Standard User WWWombat
(knowledge is power) Tue 17-Jan-17 12:13:55
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
In reply to a post by Icaras:
It's mandatory and is one of the tests that the engineers are marked and graded on for SFI jobs.


@revk definitely thinks it isn't mandatory. His further implication is that it isn't even optional!
Standard User AndyHCZ
(committed) Tue 17-Jan-17 12:21:00
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
"SFI2 is a broadband support product that tests to voice standards."

Certainly the BTWholesale Knowledge Based Diagnostics test will check most of what you've listed there. I believe they pick up something like 90% of faults for ADSL and over 95% for FTTC (this is probably higher now as tests have improved).

Most ISPs book a SFI visit when the KBD tests come back showing no fault detected. It's therefore, in most cases, a performance issue rather than a specifically clear fault.

I don't think the issue is as such Openreach and SFI, but more BT Wholesale and they way they handle performance issues or faults that they've been unable to identify with their KBD.

Edit: I should add here that you some very experienced and knowledgable support staff working at niche ISPs (like AAISP) who quite frankly, know a lot more than their support contacts within BT Wholesale. I suspect quite a lot of the BT Wholesale front line support staff have limited ISP and carrier level network training and understanding. This clearly creates an issue when an ISP has definitive evidence of a network fault (and its location) and at the same time the BT Wholesale Support staff member is unable to understand or input that fault into the system.

If you look at RevK's latest post http://www.revk.uk/2017/01/teaching-us-to-suck-eggs-... this shows a classic example of this. There will be some very experienced and knowledgeable within Openreach that AAISP could work with to resolve this, but the problem is the system and protocol from BT Wholesale does not allow this.

Edited by AndyHCZ (Tue 17-Jan-17 12:29:02)

Standard User Icaras
(experienced) Tue 17-Jan-17 12:29:48
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
In reply to a post by WWWombat:
In reply to a post by Icaras:
It's mandatory and is one of the tests that the engineers are marked and graded on for SFI jobs.


@revk definitely thinks it isn't mandatory. His further implication is that it isn't even optional!


But that would mean if an engineer got to a job and couldn't get sync on his tester he'd walk off as long as the line is up to SIN349 standards! That's not what happens though.
Standard User AndyHCZ
(committed) Tue 17-Jan-17 12:39:01
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
The base module (for end users) of a SFI visit solely checks that the line is compliant with SIN349. This is a voice line test.

It's possible that the PSTN complies to SIN349, but the broadband service isn't in sync. The engineer would find out why the broadband service isn't in sync and that would determine who is responsible for the SFI charge.
Standard User godsell4
(member) Tue 17-Jan-17 12:41:44
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
Yep, have had an engineer do that. Despite an HG612 getting a connection sometimes at 6Mb on VDSL2 for 30s and then timing out, a JDSU on the same line could not get any kind of VDSL2 connection.

PlusNet Unlimited Fibre 3Mb to 5Mb
Standard User RobertoS
(elder) Tue 17-Jan-17 13:20:34
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
PPP session? And you did mean xDSL, not ADSL which worried me.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6

Edited by RobertoS (Tue 17-Jan-17 13:22:55)

Standard User Icaras
(experienced) Tue 17-Jan-17 13:35:17
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
PPP session? And you did mean xDSL, not ADSL which worried me.


Yes, ADSL or ADSL2+, VDSL2 faults wouldn't come out as an SFI job. PPP session-it just tries to connect to the BT Wholesale test server.

Edited by Icaras (Tue 17-Jan-17 13:36:23)

Standard User RobertoS
(elder) Tue 17-Jan-17 13:36:37
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
But PPP? With where?

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6

Edited by RobertoS (Tue 17-Jan-17 13:37:06)

Standard User Icaras
(experienced) Tue 17-Jan-17 13:55:22
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
I don't really understand your question! Maybe there's a different term for it but that's what we call it anyway. The tester basically checks that it can communicate with BT Wholesale's test domain. So it's checking that there's throughput basically.

In reply to a post by godsell4:
Yep, have had an engineer do that. Despite an HG612 getting a connection sometimes at 6Mb on VDSL2 for 30s and then timing out, a JDSU on the same line could not get any kind of VDSL2 connection.


Your visit wouldn't have been an SFI, they don't exist for FTTC jobs.

We're way off topic though here! This thread is about SNR for VDSL2 and somehow we're having a conversation about the merits of SFI!

Edited by Icaras (Tue 17-Jan-17 14:01:23)

Standard User Zarjaz
(eat-sleep-adslguide) Tue 17-Jan-17 18:08:01
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
Yes but when an engineer goes out on an SFI job one of the tests they are required to do is an ADSL test on their handheld tester. This checks for errors and has a threshold, over which the test will be classed as a fail.

Except of course that the thresholds on the scripted tests are set very leniently indeed .......... It can even drop sync a few times and still deem it a pass ....... chocolate and teapot spring to mind.

You mention that these scripted tests check for a PPP session, nope, only the manual sync test (well on a JDSU at least) tests PPP, and then only to Btw test log in (this works on some LLU connections too)

Standard User Zarjaz
(eat-sleep-adslguide) Tue 17-Jan-17 18:09:51
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
Your visit wouldn't have been an SFI, they don't exist for FTTC jobs.

Yep, it would have been a "Super Fast Visit Assured'

Standard User awontroba
(regular) Tue 17-Jan-17 18:24:49
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
In reply to a post by Nightglow:
Has the 3dB rollout taken place, my exchange Kingsmead was listed, but no improvement/increase here with speed.

No change for me on the Chilton Polden exchange either. I seem to recall that the news about the roll-out starting said "from" rather than "on". I had hopes of it happening fast, but on reflection BT are probably right to not roll the change out at once to all the exchanges mentioned.

--
Adrian

Edited by awontroba (Tue 17-Jan-17 18:26:58)

Standard User Icaras
(experienced) Tue 17-Jan-17 18:25:14
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Zarjaz] [link to this post]
 
In reply to a post by Zarjaz:
Yes but when an engineer goes out on an SFI job one of the tests they are required to do is an ADSL test on their handheld tester. This checks for errors and has a threshold, over which the test will be classed as a fail.

Except of course that the thresholds on the scripted tests are set very leniently indeed .......... It can even drop sync a few times and still deem it a pass ....... chocolate and teapot spring to mind.

You mention that these scripted tests check for a PPP session, nope, only the manual sync test (well on a JDSU at least) tests PPP, and then only to Btw test log in (this works on some LLU connections too)


Oh right, Exfo does on the timed test but as you say it only works on BT Wholesale connections anyway. I've never used a JDSU.

Edited by Icaras (Tue 17-Jan-17 18:26:06)

Standard User Zarjaz
(eat-sleep-adslguide) Tue 17-Jan-17 20:30:32
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
And to be fair, who actually looks at these close out tests ...... I bet if I didn't store and upload any for a month I'd not be pulled up for it........

Standard User RobertoS
(elder) Tue 17-Jan-17 20:39:09
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: awontroba] [link to this post]
 
In reply to a post by awontroba:
No change for me on the Chilton Polden exchange either. I seem to recall that the news about the roll-out starting said "from" rather than "on". I had hopes of it happening fast, but on reflection BT are probably right to not roll the change out at once to all the exchanges mentioned.
The post with the list says:-
from Monday 16 January to select cabinets on the following exchanges (below).

A few points here though:

- ECI cabinets are excluded (I assume the new DLM is not fully tested/supported yet).
- Any line that has had the existing DLM intervene, due to poor performance, will be excluded from being moved over.
- Around 10% of lines are expected to move to the new XdB and DLM algo.
Today is Tuesday only 17 January!

Plus of course the full roll-out is:-
Currently the default target downstream noise margin is set to 6dB. From March 2017 the target downstream noise margin shall be set to either 3, 4, 5 or 6dB – the actual value shall be determined by the Dynamic Line Management (DLM) algorithm based on line stability.
That doesn't seem to mention only for Huawei cabinets but following Andy's post is seems quite possibly the case.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User awontroba
(regular) Tue 17-Jan-17 20:51:42
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Yes, we get our hopes for something happening up, then wait, and wait, and often end up disappointed.
I had missed both "select cabinets" and "10% of lines".
Probably the selection will be to aid BT/CDS in reaching targets, not to pander to speed freaks like me.

And indeed AF wrote:
We believe that some tactical deployment of vectoring and changes to the Openreach DLM (namely allowing a lower target noise margin of 3dB) may be deployed in parts of Devon and Somerset to improve the reach and speed of VDSL2.


--
Adrian

Edited by awontroba (Tue 17-Jan-17 21:00:13)

Standard User Scottish_Pete
(member) Tue 17-Jan-17 23:52:45
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Nightglow] [link to this post]
 
In reply to a post by Nightglow:
Has the 3dB rollout taken place, my exchange Kingsmead was listed, but no improvement/increase here with speed.


Don't know if was a coincident or not, but we had a power cut today from around 2pm- 2:30pm.

My SNR before was 6.1dB with a Sync of around 65000kbps

After the power was returned my stats are

xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 28402 Kbps, Downstream rate = 97804 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 74000 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 3.8 8.7
Attn(dB): 16.0 0.0
Pwr(dBm): 13.4 6.7
VDSL2 framing
Bearer 0
MSGc: -6 26
B: 174 237
M: 1 1
T: 0 42
R: 8 16
S: 0.0752 0.3781
L: 19456 5374
D: 16 1
I: 183 127
N: 183 254
Q: 16 0
V: 3 0
RxQueue: 42 0
TxQueue: 14 0
G.INP Framing: 18 0
G.INP lookback: 14 0
RRC bits: 0 24
Bearer 1
MSGc: 154 -6
B: 0 0
M: 2 0
T: 2 0
R: 16 0
S: 6.4000 0.0000
L: 40 0
D: 3 0
I: 32 0
N: 32 0
Q: 0 0
V: 0 0
RxQueue: 0 0
TxQueue: 0 0
G.INP Framing: 0 0
G.INP lookback: 0 0
RRC bits: 0 0
Counters
Bearer 0
OHF: 0 190699
OHFErr: 0 133
RS: 1816823296 2167361
RSCorr: 13275 289
RSUnCorr: 0 0
Bearer 1
OHF: 2136155 0
OHFErr: 0 0
RS: 21360934 0
RSCorr: 36 0
RSUnCorr: 0 0

Retransmit Counters
rtx_tx: 50513 0
rtx_c: 467 0
rtx_uc: 0 0

G.INP Counters
LEFTRS: 6 0
minEFTR: 74006 0
errFreeBits: 38720151 0

Bearer 0
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 587822838 0
Data Cells: 23749650 0
Drop Cells: 0
Bit Errors: 0 0

Bearer 1
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 0 0
Data Cells: 0 0
Drop Cells: 0
Bit Errors: 0 0

ES: 0 124
SES: 0 0
UAS: 22 22
AS: 34312

Bearer 0
INP: 49.00 0.00
INPRein: 0.00 0.00
delay: 0 0
PER: 0.00 3.98
OR: 0.01 64.22
AgR: 74132.27 20063.54

Bearer 1
INP: 4.50 0.00
INPRein: 4.50 0.00
delay: 3 0
PER: 16.06 0.01
OR: 79.68 0.01
AgR: 79.68 0.01

Bitswap: 24663/24663 98/98

Total time = 9 hours 32 min 14 sec
FEC: 13275 289
CRC: 0 133
ES: 0 124
SES: 0 0
UAS: 22 22
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 2 min 14 sec
FEC: 81 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 580 2
CRC: 0 1
ES: 0 1
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 9 hours 32 min 14 sec
FEC: 13275 289
CRC: 0 133
ES: 0 124
SES: 0 0
UAS: 22 22
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 0 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Since Link time = 9 hours 31 min 51 sec
FEC: 13275 289
CRC: 0 133
ES: 0 124
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0


Almost back to the speed I was getting when I first got FTTC.

Scottish_Pete

Zen Unlimited Fibre 2 connected to Local Exchange
TBB SPEEDTEST
MY BQM
Standard User Chrysalis
(legend) Wed 18-Jan-17 00:51:45
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
no idea as with the current system there is a game of chinese whispers, and the end user isnt told.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User RobertoS
(elder) Wed 18-Jan-17 01:37:53
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Scottish_Pete] [link to this post]
 
Interesting that you seem either to have a sync-time noise margin of 9dB, or you connected at a noisy time. Downstream SNRM 8.7dB.

Even more interesting is that along with that you have downstream interleaving on Bearer 1! This is highly unusual. (Bearer 1 is to do with G.INP having been implemented on lines previously on pure deep interleaving). I don't recall ever seeing that before.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User Realalemadrid
(regular) Wed 18-Jan-17 20:48:07
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
I think you've got the SNRM values the wrong way round, I read it as 3.8 down 8.7 up which would appear to agree with the previous sync speed of 65Mbps at 6.1dB. This is a common result of a power outage when the FTTC modems sync up at different times so I believe the Op is still on a 6dB target and the SNRM has fallen as other modems have come online. I am not sure about your G.INP comments, not sure what's going on there!
Standard User RobertoS
(elder) Wed 18-Jan-17 21:48:55
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Realalemadrid] [link to this post]
 
In reply to a post by Realalemadrid:
I think you've got the SNRM values the wrong way round, I read it as 3.8 down 8.7 up which would appear to agree with the previous sync speed of 65Mbps at 6.1dB.
blush Yes, you're right frown.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WWWombat
(knowledge is power) Wed 18-Jan-17 23:04:35
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Still, it is strange to see a sub-6dB SNRM alongside a Max speed that is higher than the actual.

Nonetheless, a power cut across the cabinet's coverage area is the hardest time to figure whether BT just turned on variable SNRMs.
Standard User WilliamGrimsley
(learned) Sun 22-Jan-17 16:31:04
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Yes, I'd think it's a new downstream SNR margin as the downstream attainable rate would not be higher than the rate if the line was connected at a downstream SNR margin of 6 dB but then dropped due to crosstalk.

Edited by WilliamGrimsley (Sun 22-Jan-17 16:31:20)

Standard User awontroba
(regular) Sat 28-Jan-17 14:12:21
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: awontroba] [link to this post]
 
I might have been pandered to. My line is on the Chilton Polden exchange.

My BT HH5B resynced a while ago. On connection SNR down to the lowest I have ever seen for it - 3.2

12:28:07, 28 Jan.	DSL Link Up: Down Rate=71988Kbps, Up Rate=19999Kbps; SNR Margin Down=3.2dB, Up=7.3dB

Higher upstream rates
5.	VDSL uptime:	0 days, 01:28:22
6.	Data Rate:	19999 / 71988 (was 20000 / 61660)
7.	Maximum Data Rate:	22698 / 73333 (was 25320 / 62407)
8.	Noise Margin:	7.5 / 3.3  (was 9.2 / 6.4)
9.	Line Attenuation:	22.4 / 18.1 (was 22.5 / 18.1)

And better TBB speed test results
Sat 28/01/17 13:50	63.66 Mbps	63.20 Mbps	18.58 Mbps
Sun 22/01/17 01:29	58.24 Mbps	58.15 Mbps	18.60 Mbps

I hope this is permanent and not a blip. Time will tell.

--
Adrian
Standard User sohail2k
(newbie) Wed 01-Feb-17 02:13:06
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Over the weekend (28-29th) I also noticed lower SNR marging and about 10Mb increase in sync speed

Modem Stats

Modem Stats 2

It stayed there until the morning of 31/01. Now it is back to where it was before i.e. 6db with sync speed of 47994 (1Mb up or down)
Standard User RobertoS
(elder) Wed 01-Feb-17 09:26:19
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
Does Ronski's recording give the raw xdslcmd stats please? If so, did those with the high sync and low margin show Bearer 1? If it does I expect the values for sync on it to be zero but that's fine.

I ask because that would suggest G.INP is active, and I'm fairly sure there was a post saying the low margin trial would not be used on lines with G.INP.

I don't like your 47994 current sync. That smells of banding, but the only way to know would be a re-sync which I advise against at the moment. Again the raw stats would be nice, which you can get yourself if on a Windows, without the Ronski if it doesn't give them.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User sohail2k
(newbie) Wed 01-Feb-17 14:08:59
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
I don't have the raw stats at the moment. But if you see screenshots - it says GINP enabled. INP 48. Interleaving On (8). I had G.INP enabled for a long time. Clearly I had 3db profile enabled for a couple of days with G.INP enabled.
Standard User BatBoy
(sensei) Wed 01-Feb-17 14:19:32
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
I have a 5dB target margin on a line with G.INP enabled
Standard User WWWombat
(knowledge is power) Wed 01-Feb-17 17:03:36
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
I'm not sure this is evidence of the 3dB trial.

If you had a target SNRM of 3dB, as opposed to merely running at 3dB, you would expect the attainable and actual speeds to be similar.

Your actual speed is considerably higher than your attainable, suggesting the actual SNRM (3dB) is considerably lower than the target.

Also of note is that the same situation happened on your upstream, whereas @WilliamG's line didn't show any change in upstream behaviour.

It looks more like a DSLAM restart/power-outage.
Standard User BatBoy
(sensei) Wed 01-Feb-17 17:12:17
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
In reply to a post by WWWombat:
If you had a target SNRM of 3dB, as opposed to merely running at 3dB, you would expect the attainable and actual speeds to be similar.
Unfortunately, my modem has no knowledge of the target SNRM and so my attainable is calculated as being a lot less than my actual
Standard User sohail2k
(newbie) Wed 01-Feb-17 17:14:02
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Whether its a proof or not. the point is there were changes to the SNRM which did change my sync. I did speed tests and there was a 6Mb increase.

Speed Tests

Edited by sohail2k (Wed 01-Feb-17 17:15:02)

Standard User WWWombat
(knowledge is power) Wed 01-Feb-17 17:30:32
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
Understood.

The point I was making back is that there are other reasons for what you have seen, and have been for a long time before this trial existed.

The first part of analysis now is to figure out which case you are following...
Standard User WWWombat
(knowledge is power) Wed 01-Feb-17 17:31:35
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: BatBoy] [link to this post]
 
In reply to a post by BatBoy:
Unfortunately, my modem has no knowledge of the target SNRM and so my attainable is calculated as being a lot less than my actual


Interesting. I wonder why some seem to know, and some do not?
Standard User BatBoy
(sensei) Wed 01-Feb-17 17:45:37
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
I can only comment on mine obviously. What are these other ones that seem to know?
Standard User sohail2k
(newbie) Wed 01-Feb-17 19:25:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
In reply to a post by WWWombat:
Understood.

The point I was making back is that there are other reasons for what you have seen, and have been for a long time before this trial existed.

The first part of analysis now is to figure out which case you are following...

You could be right but I am not aware of any other reason which could have lowered the SNRM. This is the first time I have see it and it was actually below 3db. Should have taken the telnet stats. If it happens next time I'll do that.

Just to mention that I live in Reading (Earley area), and the exchange is not on the list of test exchanges (someone posted a list on these forums). So not sure how we take these results.

I'll try to do a resync tonight or early tomorrow morning (15 min power cycle method).
Standard User BatBoy
(sensei) Wed 01-Feb-17 19:29:25
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
Luckily the monitoring app I use tells me the SNRM when my modem resyncs, so I know the target is 5dB.
Standard User RobertoS
(elder) Wed 01-Feb-17 21:38:36
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
In reply to a post by sohail2k:
I don't have the raw stats at the moment. But if you see screenshots - it says GINP enabled. INP 48. Interleaving On (8). I had G.INP enabled for a long time. Clearly I had 3db profile enabled for a couple of days with G.INP enabled.
Sorry, I'm not particularly familiar with that layout and didn't see the G.INP line above the table. I was looking in the table blush.

As for telnet stats, that's what I'm looking for in relation to your current sync - I see in a later post you say you will be getting those smile.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WWWombat
(knowledge is power) Wed 01-Feb-17 21:49:00
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
In reply to a post by sohail2k:
but I am not aware of any other reason which could have lowered the SNRM.


When you see the SNRM value in the modem stats, it reflects the current actual situation, not the target. The actual value varies second-by-second, depending on the noise interference encountered. Noise can change, so SNRM can change too.

A low SNRM can be seen with a normal sync speed, for example, after a new subscriber is activated. In this case, the attainable speed will be lower than the current, normal speed. Next time there is a resync, the sync speed will likely be reduced.

A low SNRM can be seen with a high sync speed, for example, after a DSLAM has been restarted, or the area has had a power cut. In this case, modems can start with a 6dB target and a higher-than-normal speed but, as other subscribers start up in parallel, the SNRM value will drop. In this case, the attainable speed will be lower than the current (excessive) speed, but will be around the normal speed for the line. Next time there is a resync, the sync speed will return back down to normal.

In your case, it looks more like the latter has happened. The attainable speed (in the screenshot) was much lower than the actual speed. A resync put everything back to normal.
Administrator MrSaffron
(staff) Thu 02-Feb-17 10:53:17
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: BatBoy] [link to this post]
 
Easy - you record a copy of the figure at the time of training, either by being passed it, or inference from the first sample after sync negotiation has completed.

Not sure that attainable is going to be reliable, as many will be based on the old relatively standard 6dB margin being fixed into the code for the maths

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User BatBoy
(sensei) Thu 02-Feb-17 11:25:42
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
That's what I think too, mine is apparently using the default of 6 to do the calculation for the attainable.
Which ones are using the actual target margin?
Standard User j0hn83
(member) Fri 03-Feb-17 03:20:14
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: BatBoy] [link to this post]
 
That doesn't make sense. Do you think your modem has synced at 5dB but it's working out it's attainable from a 6dB snrm? Because that isn't possible.
Standard User j0hn83
(member) Fri 03-Feb-17 03:47:19
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: sohail2k] [link to this post]
 
In reply to a post by sohail2k:
Understood.
You could be right but I am not aware of any other reason which could have lowered the SNRM. This is the first time I have see it and it was actually below 3db. Should have taken the telnet stats. If it happens next time I'll do that.

Just to mention that I live in Reading (Earley area), and the exchange is not on the list of test exchanges (someone posted a list on these forums). So not sure how we take these results.

I'll try to do a resync tonight or early tomorrow morning (15 min power cycle method).

If the SNRM drops and the sync rises the attainable will rise in a similar pattern. If the attainable remains what it usually is, and is considerably lower than sync, then it's almost certainly not a lower target snrm.
Standard User RobertoS
(elder) Fri 03-Feb-17 09:36:55
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
As I, MrSaffron and others have pointed out, it is entirely possible. In fact almost certainly happening. It merely requires the 6dB to be hard coded in the modem's firmware, and from several examples that appears to be the case.

How else, under the pre-existing regime, does the attainable rate significantly exceed the actual when the sync-time margin is 9dB or higher? On both VDSL2 and ADSLx, different DLMs from different suppliers.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User j0hn83
(member) Fri 03-Feb-17 11:33:09
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Hard coded in the firmware? that's a load of nonsense. It's an OpenReach setting, absolutely nothing to do with CPE firmware. The attainable is way higher when interleaving + FEC is enabled.
The max attainable rate calculation was rather loosely defined in the original VDSL2 ITU documents and many modems incorrectly calculate it, particularly when interleaving is enabled. The target SNRM is absolutely not "hard coded" in firmware.

And to add, of course it's entirely possibly. On an exchange where the trial isn't active, where only the sync had risen significantly, the attainable had remained static, I'd stick with "almost certainly not".

Edited by j0hn83 (Fri 03-Feb-17 11:41:13)

Standard User RobertoS
(elder) Fri 03-Feb-17 11:46:26
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
Openreach do not set the base figure in the modem. End of. How it is obtained is entirely up to the modem manufacturer, as you correctly point out.

The posters concerned know what they are observing and how to interpret it. They also know how their actual/attainable/SNRM behave when the Openreach base setting at the DSLAM is 6dB, and how that behaviour has changed.

You said it is impossible for the modem to be using 6dB as the base figure for calculating attainable. You cannot possibly know that for exactly the reason you state.

Similarly, all the posters (including myself) discussing the matter are fully aware of the effect interleaving has on the calculation and that the result is usually crackers.

As has been stated, the only way to be sure of the sync-time DSLAM setting is to take the stats immediately after connection, or better still from the modem log if it records it.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User RobertoS
(elder) Fri 03-Feb-17 11:49:09
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
Re one of your inclusions added while I was writing my previous reply
In reply to a post by j0hn83:
The attainable is way higher when interleaving + FEC is enabled.
Not when G.INP is active.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User Realalemadrid
(regular) Fri 03-Feb-17 11:50:49
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
I think you are misunderstanding what has been suggested and looks to be consistent with observed results, that the modem calculation of attainable rate assumes a fixed 6db SNRM and doesn't use the actual SNRM value. So the target SNRM for the attainable rate calculation is hard coded in the modem firmware.
Standard User j0hn83
(member) Fri 03-Feb-17 11:52:47
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
Re one of your inclusions added while I was writing my previous reply
In reply to a post by j0hn83:
The attainable is way higher when interleaving + FEC is enabled.
Not when G.INP is active.
That's why I didn't say G.INP. G.INP is not interleaving or FEC.
Standard User RobertoS
(elder) Fri 03-Feb-17 11:55:46
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
With G.INP active both downstream interleaving and FEC are also active. G.INP is not invoked unless interleaving is needed. By adding retransmission it is able hugely to reduce the interleaving depth.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6

Edited by RobertoS (Fri 03-Feb-17 11:57:24)

Standard User lee111s
(experienced) Fri 03-Feb-17 11:55:48
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Realalemadrid] [link to this post]
 
In reply to a post by Realalemadrid:
I think you are misunderstanding what has been suggested and looks to be consistent with observed results, that the modem calculation of attainable rate assumes a fixed 6db SNRM and doesn't use the actual SNRM value. So the target SNRM for the attainable rate calculation is hard coded in the modem firmware.


I'd also agree
Standard User j0hn83
(member) Fri 03-Feb-17 12:06:21
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Realalemadrid] [link to this post]
 
Modems shouldn't assume any target SNRM. It should actually use the set target. As seen with Williams line. Maybe, maybe the likes of a home hub made specifically for BT could do something like that, but it goes against how it's designed to work. You can't trust stats from most GUI's though, and I wouldn't trust stats from any modern they behaved in that way. Any Broadcom based or any half decent modem that works as it should, doesn't have target snrm hard coded anywhere. Using such stats to work out of you're on this trial is as helpful as peeing into the wind.
Standard User Realalemadrid
(regular) Fri 03-Feb-17 16:34:41
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
You're still not getting it. No one has suggested that the modem sets or assumes a value for the target SNRM. That is defined by DLM and the DSLAM and was normally 6dB until the trial of lower values started. The hard coded value is only used for the attainable rate calculation.
Administrator MrSaffron
(staff) Fri 03-Feb-17 17:41:45
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Realalemadrid] [link to this post]
 
I'm glad someone gets it...

Using a hard coded figure for this calculation is logical too, as it helps you see if your performance is poor due to a bad SNR environment too.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User j0hn83
(member) Fri 03-Feb-17 22:39:41
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Realalemadrid] [link to this post]
 
I know that's what you meant. I'm disagreeing with the fact the attainable is hard coded to a 6dB target. Again, as clearly seen on Williams line. His attainable is increasing as the target snrm is lowered. That's exactly as it should be, and how it is on any decent modem working as it should. I regard all Broadcom based chipsets in this category.

If a modem is using a hard coded 6dB to work out attainable, it's not working as it should, or it is designed specifically for the U.K. market on a ridiculous assumption it will always be 6dB.

In my opinion any modem that works in this way (incorrectly) shouldn't be trusted as to wether it's part of this particular trial. Doing so is as useful as peeing into the wind. "My sync has gone up and my downstream snr is 3dB" does not mean they are in the trial, especially on an exchange not on the list published. That was my original point. Using a decent modem (Broadcom for 1) and comparing the attainable is a sure way to work it out. Monitoring the stats at the time of sync would also confirm it. Again, best done with something like a Broadcom modem, that gives proper stats.

We can agree to disagree though. Opinions are like ****holes, everyone has 1, including me ;D
No offence meant, just putting my point across.
Standard User RobertoS
(elder) Fri 03-Feb-17 23:53:07
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
OK, let's take you through it. Assuming no faults on the line and SRA is not in operation. A few scenarios.

If you have a sync-time margin of 6db we can safely assume you are not on the trial, as if you were that would simply demonstrate your line is not good enough. How is the max attainable calculated, in particular what figures are used and where do they come from?

If following that sync the SNRM falls to 4dB, what happens to actual and attainable? If the SNRM rises to 8dB, what happens to actual and attainable?

Now say you have a sync-time margin of 3dB. How is the max attainable calculated, in particular what figures are used and where do they come from? Then as above, what happens with a 2dB move in either direction, assuming a drop to 1dB does not break the connection.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Administrator MrSaffron
(staff) Sat 04-Feb-17 00:29:00
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Another way

1. Line syncs to a 6dB target margin and attainable sync and actual are very close
2. DLM forces a 9dB target margin, so we now expect the attainable to still be very close to the actual, or still reflect the previous figures when it was 6dB

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User j0hn83
(member) Sat 04-Feb-17 00:42:49
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
If you have a sync-time margin of 6db we can safely assume you are not on the trial, as if you were that would simply demonstrate your line is not good enough. How is the max attainable calculated, in particular what figures are used and where do they come from?
From the DSLAM/DLM, 6dB is used
In reply to a post by RobertoS:
If following that sync the SNRM falls to 4dB, what happens to actual and attainable?
It falls, still based on a 6dB target, due to the extra noise on the line, or other factors that made the SNRM fall.
In reply to a post by RobertoS:
Now say you have a sync-time margin of 3dB. How is the max attainable calculated, in particular what figures are used and where do they come from?
Again, from the DSLAM/DLM. If the attainable was hard coded at 6dB to the firmware of the modem then the attainable would not change if the line synced with a 3dB SNRM. The example I used was Williams line. He definitely had a lower SNRM target. At the time of sync his attainable went up with his sync. It went up each time the SNRM target went down.
In reply to a post by RobertoS:
Then as above, what happens with a 2dB move in either direction, assuming a drop to 1dB does not break the connection
The attainable would drop as the actual SNRM drops.

Simply, if the attainable was hard coded to 6dB, it would NOT change with a change of target to 3dB. But it DOES change. It SHOULD change.
Not every country/ISP uses a 6dB SNRM target. The point being made to me previously was that with some modems the attainable was fixed to a 6dB SNRM target. Are you now arguing that's always the case?
Standard User j0hn83
(member) Sat 04-Feb-17 00:48:11
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
Another way

1. Line syncs to a 6dB target margin and attainable sync and actual are very close
2. DLM forces a 9dB target margin, so we now expect the attainable to still be very close to the actual, or still reflect the previous figures when it was 6dB
The fact they remain the same is because the modem uses the newer 9dB to work out the attainable. If the attainable was still being worked out from a 6dB target but the line had an actual target of 9dB, the sync and attainable would no longer be close.
Administrator MrSaffron
(staff) Sat 04-Feb-17 00:51:47
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
So why when people sync with a 9dB target do we see modems reporting attainable much higher than the sync?

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User RobertoS
(elder) Sat 04-Feb-17 01:17:56
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
Which if I remember tomorrow, (hmmm - later today LOL), I can show on my line with the telnet stats. Currently on iPad so can't. My sync-time margin is as near as dammit 9dB, sync 54999, attainable fluctuating around the mid 65Mbps area as SNRM 0.3dB or so.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User j0hn83
(member) Sat 04-Feb-17 08:44:48
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
are you talking about vdsl2?
if 6dB target gives attainable just above sync
and 9dB target gives attainable way above sync
why does 3dB target give attainable just above sync.

A 9dB target SNRM should give an attainable just above sync (on fastpath). I've never seen a 9dB target though.

It's simple! The attainable changes in a similar pattern to sync when the target snrm is lowered, remaining just above sync. This is the case on 6dB, 5dB, 4dB and 3dB. The same would happen in the other direction, only lowering together rather than increasing. If the attainable ignored the actual target SNRM the above wouldn't happen.

Sometimes, just sometimes, what you assumed to be true is wrong, and someone comes along and points it out. Today that someone is me. I've made around 20 posts on here in the past couple months. 5 or 6 of those posts someone has wrongly tried to correct me. I've been right every time smile

I have no more to say on this matter. I'm peeing into the wind.
Administrator MrSaffron
(staff) Sat 04-Feb-17 10:24:04
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
Can you point us all at any documentation for this then that details the figure being used for attainable/max rate calculations is told to the modem by the DSLAM, so will vary, and thus reflect the target margin set.

Certainly on ADSL2+ this was NOT the case, and does not seem to be the case on VDSL2.

Edited by MrSaffron (Sat 04-Feb-17 10:36:37)

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User Zarjaz
(eat-sleep-adslguide) Sat 04-Feb-17 10:34:16
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
You don't want to see that Mr.S, sounds like there may be wee on it grin

Standard User R0NSKI
(fountain of knowledge) Sat 04-Feb-17 22:11:31
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
I happen to think your correct j0hn83 smile I don't think the target is hard coded for the attainable calculation, at least not in most modems, and certainly not in Williams.

PS Anybody using HG612 stats and my GUI should have current stats recorded for each resync (dependant on settings) in the current stats folder - they have RESYNC appended and include a plink log in text format.

Standard User R0NSKI
(fountain of knowledge) Sun 05-Feb-17 09:43:57
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: R0NSKI] [link to this post]
 
Bear in mind that the stats recorded by monitoring software will not be exactly what they were at time of resync.

For instance, say there is a power cut, Modem A resync's first @ 10:05 and 6 seconds (just after HG612 logs the last stats), this will see minimum interference from disturbers who's modem haven't yet resynced. Modem A will sync much higher speed than usual at 6db, but as other modems come on line the SNR will drop. At 10:06 HG612 stats will run, and see the new resync and generate graphs for it, but the SNR will be much lower due to all the other modems that have connected over the last 54 seconds (so this is not the target SNR). In this situation the attainable will always be lower than the sync, some modems will hang fine for many weeks like this, others will create many errors and the DLM will take action. It depends on a lot of factors. If you look in the Plink log there is a value label AS, this is the uptime in seconds, the closer to 0 the more accurate the reported SNR will be to the taget.

DLStats collects data at 30 second interval's by default, so will likely be more accurate but there still a lot of room for the SNR to change prior to it being logged.

Administrator MrSaffron
(staff) Sun 05-Feb-17 10:14:54
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: R0NSKI] [link to this post]
 
So if the modem was to resync at 3,6,9,12,15 dB target, we would see an attainable very close or the same as the sync at the moment of sync? Then depending on how the real world SNR vary we would see the attainable just wander around that figure.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User R0NSKI
(fountain of knowledge) Sun 05-Feb-17 12:52:54
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
Yes, as long as the line is on G.Inp or fast path. As far as I'm aware BT FTTC doesn't have a target higher than 6, but if it did it would react the same.

If the line is at maximum sync or banded then the SNR will be higher, and the attainable will be higher than the sync.

If the attainable is lower than sync then then SNR has drifted downwards below the target SNR, that is my understanding.

Administrator MrSaffron
(staff) Sun 05-Feb-17 13:52:20
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: R0NSKI] [link to this post]
 
So how attainable works in modems is different for ADSL2+ and VDSL2?

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User j0hn83
(member) Sun 05-Feb-17 16:13:33
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
I know very little about the attainable with regards to ADSL2+. Every observation I've made with VDSL2 circuits is the attainable moves in conjunction with the target SNRM.

If the target is 6dB and the DSLAM has a reboot and the EU syncs say 10mb higher, the attainable remains what it usually is, considerably below the higher sync.

But as we're seeing this trial progress, the attainable is rising with the sync, suggesting it's using the actual target SNRM. If it was fixed at 6dB then as DLM lowered the target SNRM we would see the sync rise, but the attainable would stay the same.

This is definitely the case with modems we can record stats properly with, Broadcom & Lantiq chipsets are a couple that come to mind.

User A usually syncs at 49.9mb with attainable of 50mb
User B has identical stats.
User A's DSLAM reboots, they sync at a higher rate, still with a 6dB target.
User B resyncs as part of the SNRM trial on say the 3dB profile.
User A's new sync is 59.9mb, the attainable remains 50mb
User B's new sync is 59.9mb, the attainable rises to 60mb.

This is what is being seen in this trial. Usually the attainable wouldn't rise, as we see User A's scenario all the time.

Other chipset modems may not follow this, and may well use a fixed 6dB to work out the attainable. I really don't know as it's much more difficult to monitor locked down modems. Many ISP modems provide very little in the way of stats via GUI's that often display back to front figures, or just plain incorrect figures.
Standard User R0NSKI
(fountain of knowledge) Sun 05-Feb-17 16:26:21
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
I've no idea with ADSL, but that is my observations and understanding with VDSL.

I would think that wwwombat would be able to give a much more technical answer.

Administrator MrSaffron
(staff) Sun 05-Feb-17 19:41:43
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
Maybe it is that VDSL2 and ADSL2+ are doing things differently in the router.

Now just to find something that confirms this, rather than us all working from our observations.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User WWWombat
(knowledge is power) Mon 06-Feb-17 03:57:20
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: R0NSKI] [link to this post]
 
In reply to a post by R0NSKI:
I've no idea with ADSL, but that is my observations and understanding with VDSL.

I would think that wwwombat would be able to give a much more technical answer.


I didn't spend enough time on ADSL/2+ to note any inconsistent behaviour. And I don't think we have enough evidence of behaviour in VDSL2 with a target different from 6dB to be sure.

I think J0hn is correct in theory. The value 6 shouldn't be hard-coded, and should be gathered validly from the sync process. It is most certainly how I would write the code ...

But, and it is a big but, we have scant evidence that this is true for every modem, every firmware revision, every DSLAM type, every linecard type, every chipset type. Corners are cut, bugs exist, testing rushed and incomplete. People get things wrong, including the observations made by ourselves and related on here.

I've spent years watching and deciphering the DLM behaviour in FTTC, and can safely say it is always a mistake to make a definitive statement. Especially based on a sample of 1.

Best answer right now? Keep monitoring (thanks for that software, R0nski), and build a pool of evidence, looking for both the norm and the oddities. Expect to start figuring things it after a couple of months of honing those observations.
Standard User WWWombat
(knowledge is power) Mon 06-Feb-17 03:59:56
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
Maybe it is that VDSL2 and ADSL2+ are doing things differently in the router.

Now just to find something that confirms this, rather than us all working from our observations.


None of the protocol specs hard-code the target.

But you can't account for how software has been written. Especially if a temporary "get things working" shortcut gets left in.
Standard User WWWombat
(knowledge is power) Mon 06-Feb-17 17:42:22
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
In reply to a post by R0NSKI:
I would think that wwwombat would be able to give a much more technical answer.


I can see that, for VDSL2, the downstream target SNRM is sent from DSLAM (aka VTU-O) to the CPE modem (aka VTU-R) during the channel discovery phase. It is part of the signature data sent that includes tones, power and PSD.

The specification of the target SNRM indicates it is the same as in G.997.1 - which is common to many DSL specifications.

In reply to a post by WWWombat:
In reply to a post by MrSaffron:
Maybe it is that VDSL2 and ADSL2+ are doing things differently in the router.


It seems that VDSL2 modems are allowed to do different things.

The current G.993.2 specification includes 2 methods for calculating the attainable rate: a "basic" and an "improved" method. The basic one is mandatory, and the improved one is optional. And there are two variants of the improved method.

Worse, it seems that the one mandatory method, the "basic" one, wasn't fully specified in earlier versions of VDSL2, so the current specification recommends a vendor upgrades - but that recommendation is, of course, not mandatory.

The calculated attainable net data rate (ATTNDR) can be requested from the other end of the link (via messages on the EOC channel).

ATTNDR calculation:
https://s24.postimg.org/l5lzqdvyt/ITU_VDSL2_ATTNDR.png

"Basic" method:
https://s28.postimg.org/imthy6s1p/ITU_VDSL2_ATTNDR_b...
Note that it takes account of "all coding gains", which probably explains why it gets a higher value when FEC is turned on.

"Improved" method:
https://s29.postimg.org/80ygjon47/ITU_VDSL2_ATTNDR_i...

There's plenty of scope for variation within that lot, even if everything gets coded correctly.
Administrator MrSaffron
(staff) Mon 06-Feb-17 19:29:37
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Thanks for the time digging, seems to mean we will need to be careful about what different hardware (and maybe even firmware versions) is reporting

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User j0hn83
(member) Tue 07-Feb-17 01:48:24
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
Argh! I was sifting through my downloaded documents looking for that page when discussing this here a few days ago!
Note how all 3 listed specifically reference TARSNRM. None reference any specific figure like 6dB.
Standard User j0hn83
(member) Tue 07-Feb-17 01:58:40
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
Absolutely yes. I only trust stats from specific vdsl2 chipset vendors anyway.
Standard User Ignitionnet
(knowledge is power) Tue 07-Feb-17 12:27:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year *DELETED*


[re: R0NSKI] [link to this post]
 
Post deleted by Ignitionnet
Standard User PhilipD
(experienced) Tue 07-Feb-17 12:48:05
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
Hi

As posted in ISPreview, the 3db profile will not be rolled out on ECI cabinets.

A question to those more knowledgeabl on such things, does a line with a reduced margin which sync's higher contribute more cross talk? Or is the frequency usage and power the same, and all that is changed are the amount of bits in each tone?

Regards

Phil
Standard User MHC
(sensei) Tue 07-Feb-17 13:01:56
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: PhilipD] [link to this post]
 
They may be a very, very, very small increase in the potential contribution to cross talk. The tones in use before will stay the same and at the same power levels however there could be some increase in bits per tone - that itself could change the nature of any radiated signals picked up by other lines as cross talk - could be good or bad. It will also allow some tones which are unused due to the existing noise floor to be brought into use and those could then start radiating and giving a potential for cross talk but the other lines will see an increase in cross talk noise but as they themselves may be working with a new 3dB margin what will be the effect?


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User WWWombat
(knowledge is power) Wed 08-Feb-17 01:01:46
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MHC] [link to this post]
 
I concur with that, with an extra proviso...

The transmitter has to stay within the bounds of "total aggregate power" as well as within the bounds of the PSD mask for each individual tone.

That tends to mean that, where the modem is using a lot of tones, then some of the tones will transmit at a lower power than the PSD mask allows for.

So...

If the 3dB trial allows more tones to be used, that might cause a reduction in power of some/many/all of the other tones. There would be extra crosstalk caused by the extra tones, but there would be less crosstalk caused by the reduction in power on some of the other tones.

In theory, anyway. It depends how many lines hit the maximum aggregate power limit.
Standard User MHC
(sensei) Wed 08-Feb-17 02:06:49
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WWWombat] [link to this post]
 
I forgot that one ...

And there are probably more variables too!

Think abut this ... Margin limit drops to 3dB, so modems agree that some previously unused tones can now support 1 or 2 bits, as they are allocated the modem realised that the total power exceeds the maximum permissible and so has to reduce power marginally on all tones. That then means the tones supporting just one bit become unviable or too close to the Margin limit and are dropped. Total power is then under the max permissible so it increase the power across all tones. Then, as the limit is 3dB is brings extra tones into play ... total power goes outside and round again .... Yes, the algorithms will probably stop that happening however it has happened of systems before.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User RobertoS
(elder) Wed 08-Feb-17 09:47:58
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MHC] [link to this post]
 
In which case the two modems would never agree a sync, so the "probably" must read "certainly".

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 54999/14466Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User Icaras
(experienced) Wed 08-Feb-17 09:55:07
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
In reply to a post by MrSaffron:
Thanks for the time digging, seems to mean we will need to be careful about what different hardware (and maybe even firmware versions) is reporting


Do you not think that at present the Home Hubs at least will work out the max attainable based on 6dB? As that's the default on the Openreach FTTC system.
Standard User adamtemp
(experienced) Sat 01-Apr-17 08:21:31
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: AndyHCZ] [link to this post]
 
Looks like cab 4 on wwstal stalbridge added to trial noticed an increase today in sync and 5db snr

GLOBALNET now part of madasafish now plusnet With The same isp since 1995 ( now all part of BT) (now on a 21cn exchange wwstal 49db on adsl2 or 52.5db on adsl2+ depending on exchange sync)
Standard User lee111s
(experienced) Sat 01-Apr-17 10:49:36
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adamtemp] [link to this post]
 
The trial is finished. It's now being rolled out.
Standard User djay
(committed) Tue 04-Apr-17 12:26:44
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
My line went mad about 6 weeks ago now and my sync jumped from 56-76 and 19999 upload which it always was.
I had no way to check my stats with a plusnet hub 1 so today i plugged in my hacked hg612 and this is what i got.

I am assuming the g.inp was pushed out to test the line as it's showing ennabled and also i went from 6.5db snr down to 3.1

Here are my stats

xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 0
Last initialization procedure status: 0
Max: Upstream rate = 27024 Kbps, Downstream rate = 77340 Kbps
Bearer: 0, Upstream rate = 19999 Kbps, Downstream rate = 77632 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 3.3 15.1
Attn(dB): 15.3 0.0
Pwr(dBm): 14.0 6.6
VDSL2 framing
Bearer 0
MSGc: -6 26
B: 243 237
M: 1 1
T: 0 42
R: 10 16
S: 0.1001 0.3781
L: 20303 5374
D: 8 1
I: 254 127
N: 254 254
Q: 8 0
V: 0 0
RxQueue: 88 0
TxQueue: 22 0
G.INP Framing: 18 0
G.INP lookback: 22 0
RRC bits: 0 24
Bearer 1
MSGc: 186 -6
B: 0 0
M: 2 0
T: 2 0
R: 16 0
S: 5.3333 0.0000
L: 48 0
D: 3 0
I: 32 0
N: 32 0
Q: 0 0
V: 0 0
RxQueue: 0 0
TxQueue: 0 0
G.INP Framing: 0 0
G.INP lookback: 0 0
RRC bits: 0 0
Counters
Bearer 0
OHF: 0 440714
OHFErr: 0 0
RS: 69629480 1321951
RSCorr: 78 0
RSUnCorr: 0 0
Bearer 1
OHF: 108949 0
OHFErr: 0 0
RS: 1306646 0
RSCorr: 0 0
RSUnCorr: 0 0

Retransmit Counters
rtx_tx: 17711231 0
rtx_c: 8 0
rtx_uc: 0 0

G.INP Counters
LEFTRS: 0 0
minEFTR: 77619 0
errFreeBits: 2071995 0

Bearer 0
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 261220947 0
Data Cells: 2446303 0
Drop Cells: 0
Bit Errors: 0 0

Bearer 1
HEC: 0 0
OCD: 0 0
LCD: 0 0
Total Cells: 0 0
Data Cells: 0 0
Drop Cells: 0
Bit Errors: 0 0

ES: 0 0
SES: 0 0
UAS: 54 54
AS: 1750

Bearer 0
INP: 52.00 0.00
INPRein: 1.00 0.00
delay: 0 0
PER: 0.00 3.98
OR: 0.01 64.22
AgR: 77711.11 20063.54

Bearer 1
INP: 4.00 0.00
INPRein: 4.00 0.00
delay: 3 0
PER: 16.06 0.01
OR: 95.62 0.01
AgR: 95.62 0.01

Bitswap: 365/365 0/0

Total time = 30 min 4 sec
FEC: 78 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 54 54
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 15 minutes time = 4 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 15 minutes time = 15 min 0 sec
FEC: 39 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Latest 1 day time = 30 min 4 sec
FEC: 78 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 54 54
LOS: 0 0
LOF: 0 0
LOM: 0 0
Previous 1 day time = 0 sec
FEC: 0 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
Since Link time = 29 min 9 sec
FEC: 78 0
CRC: 0 0
ES: 0 0
SES: 0 0
UAS: 0 0
LOS: 0 0
LOF: 0 0
LOM: 0 0
#

no idea what half of that is tbh but it's a huge speed increase which is nice.

Downstream Upstream
General
rtx_tx 17711231 0
rtx_c 8 0
rtx_uc 0 0
LEFTRS 0 0
minEFTR 77619 0
errFreeBits 2071995 0
Bearer 0
RxQueue 88 0
TxQueue 22 0
G.INP Framing 18 0
G.INP Lookback 22 0
RRC Bits 0 24
Interleave depth 8 1
INP 52.00 0.00
INPRein 1.00 0.00
Delay 0 0
Bearer 1
Interleave depth 3 0
INP 4.00 0.00
INPRein 4.00 0.00
Delay 3 0
Standard User Icaras
(experienced) Tue 04-Apr-17 15:20:17
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: PhilipD] [link to this post]
 
In reply to a post by PhilipD:
Hi

As posted in ISPreview, the 3db profile will not be rolled out on ECI cabinets.

A question to those more knowledgeabl on such things, does a line with a reduced margin which sync's higher contribute more cross talk? Or is the frequency usage and power the same, and all that is changed are the amount of bits in each tone?

Regards

Phil


And yet, internally in comms to engineers Openreach haven't made a distinction between cabinet vendors. They've just said it will be rolling out nationally on a rolling basis.

I'm not saying what ISP Review are saying are wrong, but maybe an ECI solution is coming very shortly so there was no need to inform engineers it's Huawei only.
Standard User Chrysalis
(legend) Tue 04-Apr-17 23:43:11
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Icaras] [link to this post]
 
ECI is been tested during this summer on a new firmware, if and "if" its tested ok then a rollout should happen this autumn.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User troublegum
(member) Thu 06-Apr-17 15:12:45
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
I'm on an ECI cabinet and just had a resync an hour ago. Router is now showing the following:

SNR Margin (dB) 3.4 10.0
Attenuation (dB) 16.5 0.0
Output Power (dBm) 6.7 6.8
Attainable Rate (Kbps) 82532 25801
Rate (Kbps) 76057 20000

The downstream was previously at 67Mbps with a 6dB SNR margin.

Edited by troublegum (Thu 06-Apr-17 15:13:15)

Standard User WilliamGrimsley
(committed) Thu 06-Apr-17 15:20:10
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
Ooo er, the downstream SNR margin is now at 3 dB on your line! Ok, this is really confusing, so ECI cabinets are now included too? Maybe this is the reason why Openreach didn't specify that the rollout only applied to Huawei cabinets.

Sync: 40225/7660 Kbps.

Edited by WilliamGrimsley (Thu 06-Apr-17 15:21:02)

Standard User WelshWArrior
(fountain of knowledge) Thu 06-Apr-17 15:25:24
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year *DELETED*


[re: WilliamGrimsley] [link to this post]
 
Post deleted by WelshWArrior
Standard User RobertoS
(elder) Thu 06-Apr-17 15:29:51
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
Looks good. Now we have to wait and see if G.INP kicks in as well. Any idea what the Attainable was previously?

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6

Edited by RobertoS (Thu 06-Apr-17 15:30:48)

Standard User troublegum
(member) Thu 06-Apr-17 15:36:26
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
Looks good. Now we have to wait and see if G.INP kicks in as well. Any idea what the Attainable was previously?

Can't remember the exact figure, but, it was 75something Mbps. .

Edited by troublegum (Thu 06-Apr-17 15:36:48)

Standard User WilliamGrimsley
(committed) Thu 06-Apr-17 15:42:54
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WelshWArrior] [link to this post]
 
Excuse me? That's rude! This thread has nothing to do with my line stats!

Sync: 40225/7660 Kbps.
Standard User Chrysalis
(legend) Thu 06-Apr-17 22:00:40
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
I am talking g.inp profiles sorry which I should have clarified not snrm 3db rollout.

anyway, I doubt you on a 3db profile, going straight from 6db to 3db is not how openreach are rolling this out.

Sky Fibre Pro BQM - IPv4 BQM - IPv6

Edited by Chrysalis (Thu 06-Apr-17 22:02:03)

Standard User RobertoS
(elder) Thu 06-Apr-17 22:11:55
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
True. More likely it is what I experienced not long ago, a DSLAM reboot and being one of the first back online. Then cross-talk kicks in and lowers the noise margin.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User Chrysalis
(legend) Thu 06-Apr-17 22:12:50
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
yep most likely explanation, I am on 2.9db snrm myself right now on ECI and that was due to a powercut.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User WilliamGrimsley
(committed) Thu 06-Apr-17 22:28:13
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Chrysalis] [link to this post]
 
The downstream attainable rate is higher than the downstream rate. So, the downstream SNR margin is definitely 3 dB.

Sync: 40225/7660 Kbps.

Edited by WilliamGrimsley (Thu 06-Apr-17 22:29:45)

Standard User j0hn83
(member) Fri 07-Apr-17 00:01:49
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
That's an indicator, it's not that black and white though. Different modems work out attainable in different ways also. ECI cabinets don't have the lower dB profiles either so it cannot be a 3dB target.
Standard User troublegum
(member) Fri 07-Apr-17 07:17:46
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
I'm inclined to agree with William on this.

However we'll find out in a few days as I'm getting the electric meter changed out on Tuesday so power will be off for a while. Will see whether it keeps the 3dB margin when it powers back on.
Standard User WilliamGrimsley
(committed) Fri 07-Apr-17 08:16:38
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
Thanks. John, like the upstream, the downstream attainable rate is calculated at sync time, so to say it hasn't dropped to a point where it's lower than the downstream rate (if it had it would suggest a DSLAM reboot and/or a power cut so the OP's connection would've initally connected at a downstream SNR margin of 6 dB, but then it would've dropped as crosstalk increased) would backup my thoughts. However, if the downstream attainable rate was only say a few Kbps above the downstream rate, I wouldn't be so certain, but to say it's greater by several Mbps, I am.

Sync: 40225/7660 Kbps.

Edited by WilliamGrimsley (Fri 07-Apr-17 08:20:29)

Administrator MrSaffron
(staff) Fri 07-Apr-17 09:15:18
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
So are you saying attainable rate is Only calculated at sync time?

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User WilliamGrimsley
(committed) Fri 07-Apr-17 09:18:47
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
Nope, but it is calculated at sync time.

Sync: 40225/7660 Kbps.
Administrator MrSaffron
(staff) Fri 07-Apr-17 09:21:04
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
Just checking as would not want people getting the wrong idea would we

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User RobertoS
(elder) Fri 07-Apr-17 09:41:27
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
Nope, but it is calculated at sync time.
I'm not sure that is true. All we know, unless privy to each modem's firmware code, is that it is recalculated whenever its value is requested, and that for downstream at least any two consecutive values are almost always different.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WilliamGrimsley
(experienced) Fri 07-Apr-17 09:51:38
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
It is true! Then, it's continually calculated whilst the line is in sync as line conditions change.

Sync: 40225/7660 Kbps.
Standard User RobertoS
(elder) Fri 07-Apr-17 10:28:36
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
How do you know this? I don't believe you do.

There is no reason whatsoever for a programmer to build that functionality into the millisecond by millisecond processor load, when the modem has far more important things to do.

Far more likely that it is as I said - calculated on request, when we ask to see the stats. It serves no technical purpose that I can think of.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WilliamGrimsley
(experienced) Fri 07-Apr-17 10:43:06
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Because it's blatantly obvious that it updates when the line is active!

Sync: 40225/7660 Kbps.
Standard User RobertoS
(elder) Fri 07-Apr-17 10:57:04
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
There's a programme on TV named after you smile.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User ian72
(eat-sleep-adslguide) Fri 07-Apr-17 11:01:08
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
What evidence do you have? Is it that it is up to date when you look at it on the stats page or when something else reads the data? If so, as a programmer it would, as Bob says, be more sensible to calculate when it is requested rather than calculating a number over and over again that has no bearing on the operation of the modem and is purely useful to a human being looking at the screen.
Administrator MrSaffron
(staff) Fri 07-Apr-17 11:29:21
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Debate technical issues, not name calling.

The moral to this thread is that if you chase for minute detail, then others will chase you for minute detail too.

So often better to couch statements with the usual caveats e.g. in this case something along the lines of what the majority of people see when on the stats page of their device, ie. that attainable rate varies over time driven by changing parameters and appears to update every few seconds.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User RobertoS
(elder) Fri 07-Apr-17 12:20:24
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
It only updates every few seconds because the device requests an update.

To illustrate, we know the SNR by its very nature varies continuously, as it is an analogue item. It is fair to assume the SNRM itself updates in line with that, but it is not guaranteed that it does. It may be a digital calculated figure from the SNR.

It is clear that as SNR varies the max attainable varies as an analogue value, but the more one thinks about it the less feasible it becomes for the modem to know what it is. It would have to be running a calculation loop. It isn't an intrinsic part of the connection protocol.

When looking at stats on a device the figures change at fixed intervals, not continuously. The update occurs because the device requests a refresh from the modem. Exactly like all the monitoring programs. Even the GUI on a combo device does not continuously update.

There is no reason to assume the max attainable is calculated at sync-time, nor that it is continuously recalculated. It is not a figure of any use to the functioning of the modem. There is every reason to believe it is a display figure calculated on demand.

To say "it's continually calculated whilst the line is in sync as line conditions change" and "it's blatantly obvious that it updates when the line is active" has to be nonsense. It would make calculating it more important than maintaining sync, bit-swapping, and passing data.

The poster is asserting false detail, not chasing it.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6

Edited by RobertoS (Fri 07-Apr-17 12:21:06)

Standard User Jez_
(newbie) Fri 07-Apr-17 15:48:28
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
I have noticed that my line has slowly dropped over the last few days in 1db steps, down to its current 3.4db matched by a 79999 sync which i have not seen in around a year. Great news smile

I appear to have a slight issue with usable bandwidth though, my actual usable bandwidth when maxing out the line sits where it did before the changes, at just over 70mbit.

Strange one, its almost as though i have an IP profile which is stuck at the old sync rate which was that speed, which had been maintained for a long time?
Standard User WilliamGrimsley
(experienced) Fri 07-Apr-17 15:51:12
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Thanks for the in-detail explanation. I apologise, but surely there has to be a calculation somewhere in order for the attainable rate to be calculated before it displays it on the line stats page?

Sync: 40225/7660 Kbps.
Administrator MrSaffron
(staff) Fri 07-Apr-17 15:52:54
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
>but surely there has to be a calculation somewhere in order for the attainable rate to be calculated before it displays it on the line stats page?

Yes, but it may simply be triggered by loading that page, or other methods of requesting the value, i.e. calculated on the fly

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User MHC
(sensei) Fri 07-Apr-17 17:28:12
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
With experience of other comms systems, I can suggest three possible reasons for a recalc of the figure:

A specific request from a GUI or other external monitoring system.
If error rates (or another parameter) suddenly change, up or down.
On a timer - perhaps every 10 or 20 seconds and certainly not every few tens of millseconds.

There may well be others.

And as you MsS will know with your background, as this information is not vital to operations it will be a low priority task and delayed or not activated if the CPU is running at over a specific usage level.


~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

M H C


taurus excreta cerebrum vincit
Standard User j0hn83
(member) Fri 07-Apr-17 19:17:11
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
I would be very surprised if you had a 3dB target SNRM.
Every example I've seen of the new lower target has seen it drop in 1dB stages, never straight from 6dB to 3dB.
Every example has also been on Huawei DSLAMs.
You're line is connected to an ECI DSLAM and jumped straight to 3dB. I say with confidence this is not a target SNRM set by DLM.
There are dozens of reasons that cause SNRM to fall to 3dB, including new crosstalkers, DSLAM reboots, line characteristic changing, line faults, etc. The attainable being higher than sync is not conclusive. We only have limited stats, from a single moment in time. The line could be interleaved which causes the higher attainable. We don't know such modem you use, the attainable may always be considerably higher than sync.

We can say with certainty that a line has a 3dB target SNRM when we can see all the stats, recorded every minute on MyDSLWebStats, with a familiar Broadcom chipset.

With 4 lines of stats, gathered once, without knowing the modem, on an ECI DSLAM, jumping straight to 3dB without 1dB steps, I'm confident it's not a set target SNRM.
Standard User WilliamGrimsley
(experienced) Fri 07-Apr-17 19:30:28
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
Well, if those line stats don't prove to you that it's at 3 dB, then I don't know what will. wink

Router in use: Billion BiPAC 8800AXL.

Edited by WilliamGrimsley (Fri 07-Apr-17 19:30:48)

Standard User troublegum
(member) Fri 07-Apr-17 19:33:15
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
It's a Billion 8800NL and interleaving certainly is on. As I said, it'll be getting powered down on Tuesday so we'll find out then whether it retains the 3dB margin or not.
Standard User WilliamGrimsley
(experienced) Fri 07-Apr-17 19:37:39
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
I'm not discounting what John has said, neither am I saying it's definitely at 3 dB, it just looks very likely from the stats you have provided. Do you mind pasting some more detailed line stats e.g. the whole xDSL page from the web GUI? Thanks.

Router in use: Billion BiPAC 8800AXL.

Edited by WilliamGrimsley (Fri 07-Apr-17 19:38:15)

Standard User lee111s
(experienced) Fri 07-Apr-17 21:32:36
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
Or put this to bed and reboot the router tomorrow morning smile
Standard User WilliamGrimsley
(experienced) Fri 07-Apr-17 21:34:04
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
Haha, then I will look stupid! tongue

Router in use: Billion BiPAC 8800AXL.
Standard User j0hn83
(member) Fri 07-Apr-17 22:02:07
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
Well, if those line stats don't prove to you that it's at 3 dB, then I don't know what will. wink
A line that actually is on a 3dB profile? You're going solely on the current SNRM being 3dB and the attainable being higher than sync.
The user just confirmed traditional interleaving is active, which we know artificially pushes up max attainable.

The fact he's on an ECI cabinet should say it all. Unless you have some new info that this is being rolled out to ECI, before the Huawei rollout is even complete. A quick resync would confirm it either way. The target SNRM never changes on the fly, and should remain at 3dB after a resync.
Standard User troublegum
(member) Fri 07-Apr-17 22:36:13
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
Definitely not rebooting it until Tuesday smile

Edited by troublegum (Fri 07-Apr-17 22:37:56)

Standard User troublegum
(member) Fri 07-Apr-17 22:36:55
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
Since you asked

xDSL
Mode VDSL2
Traffic Type PTM
Status Up
Link Power State L0
Downstream Upstream
Line Coding (Trellis) On On
SNR Margin (dB) 3.4 10.0
Attenuation (dB) 16.5 0.0
Output Power (dBm) 6.7 6.7
Attainable Rate (Kbps) 82808 25791
Rate (Kbps) 76057 20000
B (# of bytes in Mux Data Frame) 51 236
M (# of Mux Data Frames in an RS codeword) 1 1
T (# of Mux Data Frames in an OH sub-frame) 64 5
R (# of redundancy bytes in the RS codeword) 12 16
S (# of data symbols over which the RS code word spans) 0.0218 0.3771
L (# of bits transmitted in each data symbol) 23536 5410
D (interleaver depth) 1489 1
I (interleaver block size in bytes) 64 255
N (RS codeword size) 64 255
Delay (msec) 8 0
INP (DMT symbol) 3.00 0.00
OH Frames 80440662 18213822
OH Frame Errors 29 16
RS Words 3412940271 3067448
RS Correctable Errors 103723918 217
RS Uncorrectable Errors 289 0
HEC Errors 59 0
OCD Errors 0 0
LCD Errors 0 0
Total Cells 3559643529 0
Data Cells 270135791 0
Bit Errors 0 0
Total ES 7 16
Total SES 0 0
Total UAS 0 0
Standard User fishpan
(learned) Sat 08-Apr-17 02:03:30
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
Do you have G.INP enabled by any chance?

plusnet Unlimited Fibre Extra 80/20 - sync 72200/19999 around 450m
MyDSLWebStats: fishpan
ISP Hx: Freeserve 48k > Wanadoo 56k > Tiscali 8mbps > TalkTalk 40/10 > Plusnet 80/20 > VM 200/20 > Plusnet 80/20
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 08:37:22
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year *DELETED*


[re: fishpan] [link to this post]
 
Post deleted by WilliamGrimsley

Edited by WilliamGrimsley (Sat 08-Apr-17 08:38:32)

Standard User RobertoS
(elder) Sat 08-Apr-17 09:26:05
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
In reply to a post by Jez_:
I have noticed that my line has slowly dropped over the last few days in 1db steps, down to its current 3.4db matched by a 79999 sync which i have not seen in around a year. Great news smile

I appear to have a slight issue with usable bandwidth though, my actual usable bandwidth when maxing out the line sits where it did before the changes, at just over 70mbit.

Strange one, its almost as though i have an IP profile which is stuck at the old sync rate which was that speed, which had been maintained for a long time?
Are you still with TalkTalk?

If so then you do not have an IP Profile. If you are now on a BT Wholesale based connection then going to the Further Diagnostics of the BT Wholesale Performance Test will tell you it. On a 79999Kbps sync it will be 77.4Mbps. Technically it might be 77.35 but I think that gets rounded up.

To check actual throughput speed, remember you must use a wired connection. There are too many variables affecting it on a wireless one.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User RobertoS
(elder) Sat 08-Apr-17 09:30:36
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
No, it doesn't.
?
Have I missed something, or have you been given info in PM about Jez's line stats?

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 09:42:11
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Sorry?

Router in use: Billion BiPAC 8800AXL.

Edited by WilliamGrimsley (Sat 08-Apr-17 09:46:00)

Standard User lee111s
(experienced) Sat 08-Apr-17 09:54:20
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
He quoted the post before you deleted it wink
Standard User RobertoS
(elder) Sat 08-Apr-17 09:57:04
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
Deleting a post after it has been queried, presumably as a result of that query, does not justify a followup pretending you didn't understand the query frown.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User RobertoS
(elder) Sat 08-Apr-17 09:58:48
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
Thanks lee, our posts overlapped as I was trying to find a suitable form of words for mine, which took a while smile.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 10:35:27
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
Yes, I admit it was. Sorry. I deleted it because it was of no use to the thread as I realised fishpan was talking about Jez's line stats, not another member who was talking about fishpan's line stats. I hope that makes sense! Haha!

Router in use: Billion BiPAC 8800AXL.

Edited by WilliamGrimsley (Sat 08-Apr-17 10:39:08)

Standard User simon194
(experienced) Sat 08-Apr-17 11:22:40
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
I'll put my money on the SNRM going back to 6dB after a reboot. I use a Billion 8800NL and I used to get those sorts of stats with a 3dB SNRM on and ECI cab after a power outage because the 8800's syncs up quite quickly compared to most routers
Standard User Jez_
(newbie) Sat 08-Apr-17 12:28:30
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: fishpan] [link to this post]
 
In reply to a post by fishpan:
Do you have G.INP enabled by any chance?

I am unsure about this, would this cause the symptoms i have described? (Throughput of 71mbit, maximum).

It is quite irritating, i have gained nothing from the increase in Sync as it stands.

Edited by Jez_ (Sat 08-Apr-17 12:29:20)

Standard User Jez_
(newbie) Sat 08-Apr-17 12:31:49
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
In reply to a post by Jez_:
I have noticed that my line has slowly dropped over the last few days in 1db steps, down to its current 3.4db matched by a 79999 sync which i have not seen in around a year. Great news smile

I appear to have a slight issue with usable bandwidth though, my actual usable bandwidth when maxing out the line sits where it did before the changes, at just over 70mbit.

Strange one, its almost as though i have an IP profile which is stuck at the old sync rate which was that speed, which had been maintained for a long time?
Are you still with TalkTalk?

If so then you do not have an IP Profile. If you are now on a BT Wholesale based connection then going to the Further Diagnostics of the BT Wholesale Performance Test will tell you it. On a 79999Kbps sync it will be 77.4Mbps. Technically it might be 77.35 but I think that gets rounded up.

To check actual throughput speed, remember you must use a wired connection. There are too many variables affecting it on a wireless one.


Yes i am with TalkTalk, i can assure you that the bottleneck is not within my property, all wired through a gigabit infrastructure to the router. It used to perform at 76-77mbit before crosstalk kicked in approximately one year ago. It slowly dropped to around 71mbit, and now has returned to full rate sync. Unfortunately throughput has not gained anything since the sync uplift. smile
Standard User bowdon
(committed) Sat 08-Apr-17 12:43:34
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: simon194] [link to this post]
 
I agree.

It seems every time someones stats touch 3dB there is a debate about whether he's on the 3dB SNRm.

The only way to be sure is if it stays there for a certain period, and also if a reboot after that period maintains the 3dB.

Demon => Freeserve => Pipex => Be => Sky => BT Infinity 2
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 13:07:43
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: bowdon] [link to this post]
 
Because this is a new invention and how it works is still unclear. If you don't like debates, then I wouldn't advise being on here...

Router in use: Billion BiPAC 8800AXL.
Standard User fishpan
(learned) Sat 08-Apr-17 15:45:33
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
I'm getting a similar sort of issue - DS Sync 72mbps, throughput 64mbps.

I'm on plusnet though and some plusnet users have seen a pattern emerge where *some* retransmission-enabled (G.inp) lines like mine have a distinct difference between sync and throughput. I think I made a querying post about it a while back to see if anyone else had the same issue on TBB.

I am assuming have you tried a PPP reset? (drop WAN connection, wait a min and re-enable) or if u have modem + separate router setup then just power off+on router.

plusnet Unlimited Fibre Extra 80/20 - sync 72200/19999 around 450m
MyDSLWebStats: fishpan
ISP Hx: Freeserve 48k > Wanadoo 56k > Tiscali 8mbps > TalkTalk 40/10 > Plusnet 80/20 > VM 200/20 > Plusnet 80/20
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 16:34:45
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: fishpan] [link to this post]
 
This happens on my line when the downstream SNR margin is set to 3, 4 or 5 dB with downstream G.INP.

Edited by WilliamGrimsley (Sat 08-Apr-17 16:44:32)

Standard User bowdon
(committed) Sat 08-Apr-17 18:40:52
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
I think some people like debating too much when others are looking for facts.

Demon => Freeserve => Pipex => Be => Sky => BT Infinity 2
Standard User Jez_
(newbie) Sat 08-Apr-17 18:49:47
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: fishpan] [link to this post]
 
In reply to a post by fishpan:
I'm getting a similar sort of issue - DS Sync 72mbps, throughput 64mbps.

I'm on plusnet though and some plusnet users have seen a pattern emerge where *some* retransmission-enabled (G.inp) lines like mine have a distinct difference between sync and throughput. I think I made a querying post about it a while back to see if anyone else had the same issue on TBB.

I am assuming have you tried a PPP reset? (drop WAN connection, wait a min and re-enable) or if u have modem + separate router setup then just power off+on router.


Interesting that you have a similar issue. I have actually not tried re-establishing the session. I will certainly try that and report back.

I am unsure as to how i can tell if G.INP is enabled, unfortunately the modem i am using does not respond to telnet/SSH. I do have an unlocked HG612 sitting around which i could substitute for further troubleshooting when i get some time.
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 18:52:46
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: bowdon] [link to this post]
 
What are you implying? wink

Router in use: Billion BiPAC 8800AXL.
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 18:53:51
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
Normally you can tell by the IP profile, but seen as it's wrong you can't. LOL. But, yeah, if you connect up the HG612 and look at the line stats, that will tell you. smile

Router in use: Billion BiPAC 8800AXL.

Edited by WilliamGrimsley (Sat 08-Apr-17 18:55:17)

Standard User David_W
(knowledge is power) Sat 08-Apr-17 20:52:35
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Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
Normally you can tell by the IP profile, but seen as it's wrong you can't. LOL. But, yeah, if you connect up the HG612 and look at the line stats, that will tell you. smile
DLM sets the SNR margin target on synchronisation. All the router can tell you is the instantaneous SNR margin, which is not necessarily the target applied at synchronisation even if you ask within a couple of minutes of booting the router.

A post that says "I seem to be on 3dB SNR margin" is much more likely at present to have been a line that resynchronised at a low noise time and is currently operating in a higher noise environment rather than a line with a 3dB SNR margin target. It is believed that DLM steps down from 6dB to 3dB SNR margin target in 1dB increments, so someone who has a 3dB SNR margin target applied would expect to have seen several resynchronisations over a period of time, each with improving speed as DLM homed in on the lower SNR margin target.


Correlation does not equal causation.



ZeN Unlimited Fibre 2 with native IPv6
thinkbroadband speed test : speedtest.net : thinkbroadband quality monitor IPv4 IPv6
Standard User WilliamGrimsley
(experienced) Sat 08-Apr-17 21:00:45
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: David_W] [link to this post]
 
I'm talking about the IP profile not the SNR margin. wink

Router in use: Billion BiPAC 8800AXL.
Standard User David_W
(knowledge is power) Sun 09-Apr-17 10:44:09
Print Post

William - some thoughts


[re: WilliamGrimsley] [link to this post]
 
As you may well have realised, William, this forum has been here for a very long time. It has, amongst its members, many people with deep technical backgrounds. Some here work or have worked for companies including Openreach and others associated with UK broadband. They mostly cannot reveal their affiliation, but those of us who have been here long enough know who they are and something of their background or experience. Others, including myself, have experience that speaks to UK broadband - I am a former software engineer for a company that worked on early ATM implementations, also I have contributed code and bug fixes to pfSense as well as a few small contributions to FreeBSD.

My knowledge of ATM is essentially useless now, as the ATM that remains in public networks is rapidly being replaced by "pure IP" / Ethernet technologies such as MPLS. In particular, what is left of the ATM based 20CN is being replaced by the MPLS based 21CN. Nevertheless, that professional experience and my subsequent involvement in the open source community gives me 'real life' experience of working with supposed standards and how actual implementations diverge from standards in sometimes surprising ways. These divergences are often hidden from public view by commercial confidentiality, sometimes because companies don't want to admit to the embarrassing shortcomings of their products. In one case, a software product I was working on kept failing on a subset of servers my former employer had manufactured. It turned out that the reason was a subtle firmware bug in a particular range of hard disks that the (well regarded at the time) drive manufacturer admitted was a known bug only when I had carefully worked out the failure scenario with the help of a logic analyser hooked up to a hard disk and my colleagues had engaged in a Friday afternoon software lab exercise of "who can get the most errors per second out of the hard disk" to verify my results. Points scoring, of the sort you seem to enjoy, would have got us nowhere - the last thing we needed was further levels of untested speculation obscuring our thinking. It was a case of using the scientific method: setting up a reasonable hypothesis, collecting data and seeing whether the data supported the hypothesis or whether a new hypothesis was needed.

It turned out that there was a firmware bug affecting the hard disk's caching on the last physical track leading to it throwing a bus error if you carried out too much random I/O on the last few hundred sectors (it could well have been an 'off by one' type bug, though that's speculation on my part). In most usage scenarios this bug would have been benign but our product used the last portion of the disk as a staging area for print jobs so these disks flaked out when printing. The answer was to deploy an (unfortunately non-backward compatible) change in our partitioning strategy to move the print staging area to between the first and second partition, rather than placing it at the end of the disk. These were the days before flash memory; the drive firmware was on a plug in PROM and the only other version the manufacturer would offer us was PROMs for an earlier version that we already knew from previous work to have totally broken caching, so deploying fixed drive firmware was a non-starter.

These days, there are lots of publicly viewable examples of these surprises. You only need to delve into the source code repositories and bug databases of open source projects such as the open source routers pfSense and OpenWRT to see how the code is littered with work-rounds for surprises which include:
  • divergent implementations of a standard, often as a result of lax wording of the standard or an unforeseen case
  • incorrect implementation of a standard
  • multiple ways of implementing the same thing (for example the number of different ways that IPv6 connectivity is provided at the moment: DHCP-PD, 6RD, statically routed IPv6, various flavours of IPv6 in IPv4 tunnelling)
  • the 'reference implementation' being wrong, but everyone feels compelled to replicate the error in order to provide interoperability (particularly vile, as the 'reference implementation' should be fixed, but it happens)
  • continuing need to support an earlier, incompatible version of the standard

Your enthusiasm about DSL and broadband is not in doubt, but your contributions to threads such as this one which are short and not carefully thought through do not help the discussion. You scored a point off me by tricking me into placing my reply in a part of the thread that was about BTw's IP Profile - but I read in flat view, as I find the threaded view on this ancient forum software to be intolerably clunky to use and got confused by the divergence from the main topic of the thread. Rather than focusing on the (entirely meaningless) point you scored off me, I suggest you reflect on the substance of the post. You have been quick to suggest that any posted statistics showing a 3dB SNR margin are an example of a 3dB downstream target SNR margin, ignoring:
  • SNR margin changes over time
  • the SNR margin shortly after the router has resynchronised is not necessarily the target SNR margin
  • Openreach's (proprietary) DLM implementation is believed to reach a 3dB target SNR margin in 1dB steps, starting from 6dB
  • the rollout of <6dB target SNR margin is currently believed to be Huawei only and not to have spread that far from the trial area in Devon and Cornwall
  • statistics copied and pasted from many router web interfaces contain errors - command line interfaces are typically more reliable

We are trying to understand the extent and behaviour of this new departure in DLM. Jumping to unwarranted conclusions that throws everyone off the scent does not help in this task.


In another thread you asked some entirely reasonable questions about IPv6. I attempted to answer those questions in ways that provided information, sparked your interest and potentially gave you a basis for experimentation. IPv6 isn't going to go away; it is the future of the Internet, yet it is an area that many of us still understand poorly. These days, you have a wealth of tools for self-education available free of charge: packet sniffing software (Wireshark), hypervisors (such as Virtualbox) together with a wealth of pre-configured VMs (routers such as pfSense as well as client operating systems), IPv6 tunnels if you don't have native IPv6 (Hurricane Electric) as well as the IPv6 standards (any web site that carries RFCs) and related discussion (Google, used wisely, is your friend!) are all available to you. I doubt anyone will judge you for asking reasonable questions and making mistakes when trying to understand things; I've certainly made my share of mistakes and been willing to accept correction and criticism from others.

I encourage you to experiment and learn, as well as continuing to engage with these forums. Whilst some information, such as the behaviour of Openreach's FTTC DLM, is not freely available, there is a lot of freely available technical information and resources for self-learning. Meanwhile, I suggest that it would help everyone if your posts are a little more reflective, acknowledge lack of certainty whenever appropriate, do not jump to unwarranted conclusions, recognise that correlation does not imply causation and that you focus less on "scoring points".



ZeN Unlimited Fibre 2 with native IPv6
thinkbroadband speed test : speedtest.net : thinkbroadband quality monitor IPv4 IPv6
Standard User WilliamGrimsley
(experienced) Sun 09-Apr-17 11:12:55
Print Post

Re: William - some thoughts *DELETED*


[re: David_W] [link to this post]
 
Post deleted by MrSaffron

Edited by WilliamGrimsley (Sun 09-Apr-17 11:25:24)

Standard User RobertoS
(elder) Sun 09-Apr-17 11:42:57
Print Post

Re: William - some thoughts


[re: WilliamGrimsley] [link to this post]
 
The trouble is, William, that although your thoughts are usually based on facts you have gleaned since coming to these forums, your conclusions are often hypothesis stated as fact.

These are difficult to refute because of that factual content when nobody knows the full facts as Openreach guard then very closely. However, your conclusions are often highly dubious and could well contribute to the plethora of internet myths, which are the bane of every one of us trying to help people who have found them on google and therefore believe them.

You can be wrong. You used to be so very frequently, but as your knowledge has increased the frequency has decreased. You are still not perfect, none of us are. You are about the only person claiming to be 100% correct.

You are yourself the cause of people disputing your conclusions, because those conclusions are rarely fully supported by what is known. They are often conjecture.

You frequently point out that debate is all you are engaging in when you make questionable statements, but as soon as anyone challenges such dubious statements you complain they are trying to stifle debate.

It is you that refuses to debate and get all uppity as now when people challenge your statements. You refuse to accept that you may be wrong even though it cannot be proved that you are.

All you really need to do is start introducing phrases like "I think ..." and "It's possible that ..." and "it looks as if ...", even "In my experience ..." into your discourse when you are extrapolating from partial knowledge.

There's no need for profanity either. It isn't the stuff of sensible discussion.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6

Edited by RobertoS (Sun 09-Apr-17 12:03:01)

Administrator MrSaffron
(staff) Sun 09-Apr-17 11:54:37
Print Post

Re: William - some thoughts *DELETED*


[re: WilliamGrimsley] [link to this post]
 
This forum has rules on the use of inappropriate language and the post that has been deleted broke those rules.

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User RobertoS
(elder) Sun 09-Apr-17 12:01:56
Print Post

Re: William - some thoughts


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
I understand how DSL works, thank you very much.
You do not! Even Openreach don't fully, because if they did they would fix its faults and roll it out in fully working order on all cabinets. But many here know a lot more about it than you seem to. I don't claim to "know" how it works. Nobody else here claims that either.
This "point scoring" is wrong. I come on here to offer my advice and help others, not to be taught constantly about where I've gone wrong.
You are now claiming that even when you are wrong in whatever way that nobody should correct you.

What?

It doesn't help others if what you state as fact is not necessary so. Bear in mind not just the people present today read your posts, thousands are likely to over the next year or so when they come up in search engine results. You should welcome correction, it's the only way any of us learn where we are going wrong.

It's also the way potential internet myths are avoided, as long as the people finding them go on to read the responses. Unfortunately they often just accept the statement and go away happy, but misled.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 63790/13596Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User David_W
(knowledge is power) Sun 09-Apr-17 12:02:49
Print Post

Re: William - some thoughts


[re: WilliamGrimsley] [link to this post]
 
I'm not going to get drawn into a pointless ad hominem argument; that helps nobody. However, it is not your right to say "let's leave this here and move on" (as you did in the post that MrSaffron has deleted). A discussion conducted without a chair does not resolve based on the sole prerogative of a single participant. I am exasperated that the vast majority of my replies to you involve me pointing out your erroneous conclusions and/or responding to your firm statements of 'fact' which are either incorrect or where the evidence is incapable of supporting the firm conclusion(s) you have drawn. If you draw conclusions, you must be prepared to have your conclusions challenged with reasoned arguments to the contrary. If you are unsure, either do not reply or reply with some acknowledgement of the uncertainty in what you are saying.

True reputation on forums like this is established not by forum rank (which, with a few exceptions, is just a lookup based on number of posts - so people like yourself who make a lot of one sentence replies will soon get to the higher ranks). Rather, reputation is established based on track record. Please ask yourself what sort of reputation you are gaining.


If you knew me well, you would know that I am well acquainted with severe health problems; I have had a complex neuromuscular condition for over twenty years. When a duty exists under the Equality Act 2010 and related enactments to offer accommodation to disabled people, this duty is based on the concept of "reasonable adjustments". We all contribute here according to our personal whims and subject to the rules of the forum. Inasmuch as the forum operators are a service provider, they owe you some duties in respect of reasonable adjustments, which are largely understood to be an anticipatory duty to do with technical accessibility features of the forums such as compatibility with screen reader software.

These forums are essentially a social setting, albeit one based on interest in a particular area. Part of participating in any social setting is accepting the reasonable consequences of your own actions. Nothing in the 2010 Act constrains the actions of other forum users towards you - one would hope they display courtesy and consideration, as I am attempting to do, but you can expect nothing more. I do not wish to cause you distress, but you must accept that nothing in your health condition gives you the right to dictate how I or others behave towards you (as you sought to do in the post that has been deleted). Even when there is a right to reasonable adjustments under law, a disabled person does not have the right to insist on any particular adjustment.


If you require social support to participate in online discussion, I suggest that you attempt to seek that support. Unfortunately the criteria for Personal Independence Payment only considers the need for social support in face-to-face scenarios.



ZeN Unlimited Fibre 2 with native IPv6
thinkbroadband speed test : speedtest.net : thinkbroadband quality monitor IPv4 IPv6

Edited by David_W (Sun 09-Apr-17 12:16:36)

Standard User WilliamGrimsley
(experienced) Sun 09-Apr-17 12:11:34
Print Post

Re: William - some thoughts *DELETED*


[re: MrSaffron] [link to this post]
 
Inappropriate language?!

Router in use: Billion BiPAC 8800AXL.
Standard User WilliamGrimsley
(experienced) Sun 09-Apr-17 12:13:59
Print Post

Re: William - some thoughts


[re: RobertoS] [link to this post]
 
Ok, thanks for the advice. I don't claim to be 100% correct, that would be wrong, because as you say, no one can be. I'll try and not come over like this again. Sorry.

Router in use: Billion BiPAC 8800AXL.
Standard User WilliamGrimsley
(experienced) Sun 09-Apr-17 12:14:45
Print Post

Re: William - some thoughts


[re: David_W] [link to this post]
 
Let's just leave it, David... But, anyway I am leaving for good. I have better things to do than being drawn in to this rubbish!

Router in use: Billion BiPAC 8800AXL.

Edited by WilliamGrimsley (Sun 09-Apr-17 12:16:01)

Standard User j0hn83
(member) Sun 09-Apr-17 15:33:19
Print Post

Re: William - some thoughts


[re: David_W] [link to this post]
 
Very informative post. Slight correction in that the trial is over now and not limited to the Devon & Cornwall area. It's been on a phased rollout since at least the 20th March. OpenReachs retransmission rollout was circa 45k lines per day, so I'd expect this to be right across the country by now.

A little knowledge can be a dangerous thing. Williams experience of how Broadcom VDSL2 chipsets handle the max attainable seems to have clouded every other fact. Every piece of info we've had suggests this is for Huawei cabinets only. I've seen nothing to suggest this has reached a single ECI cabinet. With the delay to ECI retransmission I would expect this to remain the case. Though as with most things OpenReach DLM related, this is best guess and by no means fact.
Standard User wolvesmad
(fountain of knowledge) Mon 10-Apr-17 11:02:36
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
I used to get a full sync before the dreaded cross talk kicked in and took my connection down to 62/20 where it has stayed for 18 months.

3 weeks ago we had a power cut and my HG612 must have beaten the other routers and connected at full sync again. It stayed at full sync until yesterday when I had to turn the mains off, the HG612 was displaying a 0.1db sync in the evenings, noticed ping spikes etc at night.

According to BQM my line dropped this morning. I'm not on an ECI cab so will maybe they are dropping my target SNR down.

-

BT BroadbandInfinity 2
Standard User Jez_
(newbie) Mon 10-Apr-17 12:01:10
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: fishpan] [link to this post]
 
In reply to a post by fishpan:
I'm getting a similar sort of issue - DS Sync 72mbps, throughput 64mbps.

I'm on plusnet though and some plusnet users have seen a pattern emerge where *some* retransmission-enabled (G.inp) lines like mine have a distinct difference between sync and throughput. I think I made a querying post about it a while back to see if anyone else had the same issue on TBB.

I am assuming have you tried a PPP reset? (drop WAN connection, wait a min and re-enable) or if u have modem + separate router setup then just power off+on router.


To come back to you on this, re-establishing the session has resolved my issue - thankyou for suggesting that as i didnt imagine that this would make any difference. Simply resyncing the line instantly didnt do the trick, i had to leave the connection down for a period of time. (I actually left it down for 30mins).

Does anybody have a technical explanation of why this was the case? My throughput is now at 77mbit (against my new 3.4db SNR 79999 sync).

Thankyou again for the suggestion, that is a very nice little tweak from openreach there. smile

Edited by Jez_ (Mon 10-Apr-17 12:01:47)

Standard User Jez_
(newbie) Mon 10-Apr-17 12:07:58
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: wolvesmad] [link to this post]
 
In reply to a post by wolvesmad:
I used to get a full sync before the dreaded cross talk kicked in and took my connection down to 62/20 where it has stayed for 18 months.

3 weeks ago we had a power cut and my HG612 must have beaten the other routers and connected at full sync again. It stayed at full sync until yesterday when I had to turn the mains off, the HG612 was displaying a 0.1db sync in the evenings, noticed ping spikes etc at night.

According to BQM my line dropped this morning. I'm not on an ECI cab so will maybe they are dropping my target SNR down.


Pretty much mirrors my experiences, except i dropped from 79999 down a couple of years ago, to around 71000 due to crosstalk. I did used to get occasional fast sync events after power outages too, just like you. The SNR would gradually creep down to 3.5db or so until unfortunately i had to cut the power or reboot etc. It would hold for as long as i kept the sync going.

This is why i was confident that when OR finally reduced my actual target, i would get reliable full rate syncs every time. It has proven to be the case, the line last synced at 3.4db @ 79999 mid afternoon yesterday.

You'll notice the target SNR gradually reducing, in my case my line seemed to have a target of 6.4db, i then over a period of a few days i found the line re-syncing in the middle of the night every 2 days at around 2am, in 1db reduced increments. Night 1 was 5.4db@~74000, night 3 was 4.4db@~76000, then finally night 5 was 3.4db@79999.

Edited by Jez_ (Mon 10-Apr-17 12:10:46)

Standard User wolvesmad
(fountain of knowledge) Mon 10-Apr-17 12:13:29
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
Doubt i'll see 79999 until the next power cut but it'll be interesting to see where DLM takes my current sync of just over 62.

A stable low 70's sync would be nice.

-

BT BroadbandInfinity 2
Standard User Jez_
(newbie) Mon 10-Apr-17 12:21:50
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: wolvesmad] [link to this post]
 
In reply to a post by wolvesmad:
Doubt i'll see 79999 until the next power cut but it'll be interesting to see where DLM takes my current sync of just over 62.

A stable low 70's sync would be nice.


I personally found that each 1DB reduction gave me around 3mbit, for reference.

I'd therefore bet you'll definitely see a solid low 70s, report back when it happens smile

Edited by Jez_ (Mon 10-Apr-17 12:22:07)

Standard User troublegum
(member) Tue 11-Apr-17 13:55:22
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
In reply to a post by j0hn83:
I would be very surprised if you had a 3dB target SNRM.
Every example I've seen of the new lower target has seen it drop in 1dB stages, never straight from 6dB to 3dB.
Every example has also been on Huawei DSLAMs.
You're line is connected to an ECI DSLAM and jumped straight to 3dB. I say with confidence this is not a target SNRM set by DLM.
There are dozens of reasons that cause SNRM to fall to 3dB, including new crosstalkers, DSLAM reboots, line characteristic changing, line faults, etc. The attainable being higher than sync is not conclusive. We only have limited stats, from a single moment in time. The line could be interleaved which causes the higher attainable. We don't know such modem you use, the attainable may always be considerably higher than sync.

We can say with certainty that a line has a 3dB target SNRM when we can see all the stats, recorded every minute on MyDSLWebStats, with a familiar Broadcom chipset.

With 4 lines of stats, gathered once, without knowing the modem, on an ECI DSLAM, jumping straight to 3dB without 1dB steps, I'm confident it's not a set target SNRM.


You were of course correct.

After the scheduled power outage this morning, I am back to an SNR margin of just above 6dB and a sync speed of 66776kbps frown

Move along, nothing to see here.
Standard User j0hn83
(member) Tue 11-Apr-17 15:19:35
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: troublegum] [link to this post]
 
In reply to a post by troublegum:
You were of course correct.

After the scheduled power outage this morning, I am back to an SNR margin of just above 6dB and a sync speed of 66776kbps frown

Move along, nothing to see here.

Thanks for letting us know

In reply to a post by WilliamGrimsley:
Well, if those line stats don't prove to you that it's at 3 dB, then I don't know what will. wink
You were saying? smile
That's why you shouldn't state your opinion as fact.
Standard User adslmax
(knowledge is power) Tue 11-Apr-17 18:58:15
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: wolvesmad] [link to this post]
 
In reply to a post by wolvesmad:
I used to get a full sync before the dreaded cross talk kicked in and took my connection down to 62/20 where it has stayed for 18 months.


I was very lucky man as my sync rate stay at 79999/19999 for 37 months now since Feb 2014.

My sync below:

Downstream Upstream
Line Coding (Trellis) On On
SNR Margin (dB) 10.1 16.3
Attenuation (dB) 11.3 0.0
Output Power (dBm) 12.5 -1.3
Attainable Rate (Kbps) 93352 29324
Rate (Kbps) 79999 19999

Edited by adslmax (Tue 11-Apr-17 18:59:42)

Standard User MrShabz
(newbie) Tue 18-Apr-17 10:25:50
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
My line has dropped to 3.2dB from 5.9dB downstream, gained about 8000Kbps.

But my upstream has increased to 6.3dB from 5.1dB, loosing around 2000Kbps.

Is this what we should expect to see when BT change the target SNRm?

Thanks

NEW
# xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 1
Last initialization procedure status: 0
Max: Upstream rate = 16348 Kbps, Downstream rate = 61688 Kbps
Bearer: 0, Upstream rate = 16348 Kbps, Downstream rate = 62987 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 3.2 6.3
Attn(dB): 18.8 0.0
Pwr(dBm): 13.1 7.5


OLD
# xdslcmd info --stats
xdslcmd: ADSL driver and PHY status
Status: Showtime
Retrain Reason: 1
Last initialization procedure status: 0
Max: Upstream rate = 18063 Kbps, Downstream rate = 51820 Kbps
Bearer: 0, Upstream rate = 18131 Kbps, Downstream rate = 54017 Kbps
Bearer: 1, Upstream rate = 0 Kbps, Downstream rate = 0 Kbps
Link Power State: L0
Mode: VDSL2 Annex B
VDSL2 Profile: Profile 17a
TPS-TC: PTM Mode(0x0)
Trellis: U:ON /D:ON
Line Status: No Defect
Training Status: Showtime
Down Up
SNR (dB): 5.9 5.1
Attn(dB): 18.7 0.0
Pwr(dBm): 13.1 7.6
Standard User fishpan
(learned) Tue 18-Apr-17 10:58:33
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrShabz] [link to this post]
 
Did it drop in roughly 1db increments or just go straight from 6 to 3db? If the former, then its very likely it is the new 3db target if the latter then it is most likely something such as a DSLAM reboot after which you synced quicker than other users. The crosstalk of other users syncing would then bring the SNR down.

plusnet Unlimited Fibre Extra 80/20 - sync 72200/19999 around 450m
MyDSLWebStats: fishpan
ISP Hx: Freeserve 48k > Wanadoo 56k > Tiscali 8mbps > TalkTalk 40/10 > Plusnet 80/20 > VM 200/20 > Plusnet 80/20
Standard User wolvesmad
(fountain of knowledge) Tue 18-Apr-17 11:14:31
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
I'm unfortunately in an un cabled area so if you want high speeds, you have to go with BT = cross talk.

-

BT BroadbandInfinity 2
Standard User adslmax
(knowledge is power) Tue 18-Apr-17 15:56:44
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: wolvesmad] [link to this post]
 
In reply to a post by wolvesmad:
I'm unfortunately in an un cabled area so if you want high speeds, you have to go with BT = cross talk.


I thought cable is covered all over Telford. Are you sure your area isn't covered by VM cable?
Administrator MrSaffron
(staff) Tue 18-Apr-17 16:11:49
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
https://labs.thinkbroadband.com/local/broadband-map#...

Lots of gaps in the cable coverage

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User adslmax
(knowledge is power) Tue 18-Apr-17 16:19:17
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: MrSaffron] [link to this post]
 
Thanks as there is cable around Hollinswood area (believed that wolvesmad live there)
Standard User wolvesmad
(fountain of knowledge) Tue 18-Apr-17 18:30:12
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: adslmax] [link to this post]
 
I don't live in Hollinswood but I'm on the Hollinswood exchange.

All the modern post mid 90's houses around here are BT only. Due to the long lines the fiber take up is very high.

My line stats apart from SNR and attainable rate are pretty much identical to yours.

I can get 79999/20000 sync if there is a powercut as my HG612 syncs fast and beats most of the other routers.

Cable isn't up to much in the areas that have it in TF2 anyway according to the VM message board. I'd rather a solid 62/20 sync than a slow jittery cable connection at peak times.

-

BT BroadbandInfinity 2
Standard User fishpan
(learned) Thu 20-Apr-17 23:12:07
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: fishpan] [link to this post]
 
Is this rollout still continuing? Haven't seen any new snr target resyncs on MyDSLWebStats for a while. I know its a small sample size but still wondering if they have paused to take a look at results.

plusnet Unlimited Fibre Extra 80/20 - sync 72200/19999 around 450m
MyDSLWebStats: fishpan
ISP Hx: Freeserve 48k > Wanadoo 56k > Tiscali 8mbps > TalkTalk 40/10 > Plusnet 80/20 > VM 200/20 > Plusnet 80/20
Standard User RobertoS
(elder) Fri 21-Apr-17 01:49:51
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: fishpan] [link to this post]
 
I read a comment somewhere fairly authoritative, maybe ISPreview or Kitz forums, that it went from the initial trial to a slightly bigger coverage around the trial area at the "end" of the trial period, but that national rollout had been delayed until September.

I don't know how true that is, but from similar observations to yours it looks as though it may be.

Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 65273/13554Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User j0hn83
(member) Fri 21-Apr-17 15:10:57
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
National rollout stayed on 20th March to all Huawei cabinets.
It's ECI retransmission that's delayed till September I believe. That would likely tie in with ECI getting 3dB SNRM.
http://forum.kitz.co.uk/index.php/topic,19508.0.html
That was an email to OpenReach engineers ^^

Edited by j0hn83 (Fri 21-Apr-17 15:12:31)

Standard User Jez_
(newbie) Fri 21-Apr-17 15:38:05
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
I read a comment somewhere fairly authoritative, maybe ISPreview or Kitz forums, that it went from the initial trial to a slightly bigger coverage around the trial area at the "end" of the trial period, but that national rollout had been delayed until September.

I don't know how true that is, but from similar observations to yours it looks as though it may be.


It must be fairly wide, i have VDSL connections in Oxfordshire at Aston nr Witney, and Shiplake down near Henley-on-Thames, and Bradford-on-Avon in Wiltshire. All are now at 3db targets.
Standard User lee111s
(fountain of knowledge) Fri 21-Apr-17 15:46:52
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
In reply to a post by Jez_:
In reply to a post by RobertoS:
I read a comment somewhere fairly authoritative, maybe ISPreview or Kitz forums, that it went from the initial trial to a slightly bigger coverage around the trial area at the "end" of the trial period, but that national rollout had been delayed until September.

I don't know how true that is, but from similar observations to yours it looks as though it may be.


It must be fairly wide, i have VDSL connections in Oxfordshire at Aston nr Witney, and Shiplake down near Henley-on-Thames, and Bradford-on-Avon in Wiltshire. All are now at 3db targets.


It's nationwide.
Standard User RobertoS
(elder) Fri 21-Apr-17 16:50:45
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: j0hn83] [link to this post]
 
From a link to ISPreview in the Kitz thread you linked to, in fact to the article I referred to earlier that I recalled reading but wasn't sure where, smile.
UPDATE 18th March 2017

A little more detail has come in so I figured we’d add it. Initially Openreach expect to add the new feature to 680,000 Huawei lines between 20th to 31st March 2017 and around 96,000 of those are likely to see a direct benefit as the DLM system will apply a sub-6dB profile (any rate capped and performance managed lines should expect to be excluded).

At this point we understand that Openreach may pause the deployment to assess the initial roll-out and then continue it towards completion by September 2017.


Kindness isn't going to cure the world of all its awfulness but it's a good place to begin. Daisy Ridley.
My broadband basic info/help site - www.robertos.me.uk. Domains, site and mail hosting - Tsohost.
Connection - AAISP Home::1 80/20. Sync 65273/13554Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User Zarjaz
(eat-sleep-adslguide) Fri 21-Apr-17 18:31:28
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Jez_] [link to this post]
 
and Shiplake down near Henley-on-Thames,

An area I know well ...... cab 1, 2 or the newbie one up at the cross roads ?

Standard User cleeve555
(newbie) Wed 26-Apr-17 06:48:46
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Zarjaz] [link to this post]
 
If the customers modem is not restarted, will the line sync rate be renegotiated while both modems are up and running in a normal condition?

Connection - Zen Fibre 1 Broadband VDSL/2 at 34M/10Mbps on BT Openreach
Standard User lee111s
(fountain of knowledge) Wed 26-Apr-17 08:51:57
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: cleeve555] [link to this post]
 
DLM can force a resync.
Standard User Zarjaz
(eat-sleep-adslguide) Wed 26-Apr-17 09:40:58
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: cleeve555] [link to this post]
 
If the customers modem is not restarted, will the line sync rate be renegotiated while both modems are up and running in a normal condition?

Only if you live in Shiplake ??? smile

Seriously, as Lee says, DLM can force a resin if it sees fit.

Standard User cleeve555
(newbie) Fri 28-Apr-17 09:02:17
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: lee111s] [link to this post]
 
Thanks.

I am now seeing DLM increase the speed since the cutover to FTTC / VDSL on 21st April.

The modem router has not been restarted since the 21st, and have seen a number of speed increases:
9999 38791 28-Apr-2017 04:39
9996 34781 27-Apr-2017 08:11
9996 33170 26-Apr-2017 14:01
9996 33065 24-Apr-2017 07:42

Zen Fibre 1 service is quoted as 38Mbps down and 9.5Mbps up, so looks like I am now close to these limits?

Connection - Zen Fibre 1 Broadband VDSL/2 at 34M/10Mbps on BT Openreach
Standard User RobertoS
(elder) Fri 28-Apr-17 09:04:20
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year *DELETED*


[re: cleeve555] [link to this post]
 
Post deleted by RobertoS
Standard User David_W
(knowledge is power) Fri 28-Apr-17 09:35:55
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: cleeve555] [link to this post]
 
In reply to a post by cleeve555:
Zen Fibre 1 service is quoted as 38Mbps down and 9.5Mbps up, so looks like I am now close to these limits?
You are now pretty close. The actual sync speed limitation is 39999 kbit/s down and 9999 kbit/s up (or possibly 1 higher on each). However, the advertising rules applying to all ISPs mean that they can only quote a speed that at least 10% of customers achieve in practice.



ZeN Unlimited Fibre 2 with native IPv6
thinkbroadband speed test : speedtest.net : thinkbroadband quality monitor IPv4 IPv6
Standard User Jez_
(newbie) Fri 28-Apr-17 13:36:03
Print Post

Re: Openreach to rollout 3dB target SNRm for FTTC next year


[re: Zarjaz] [link to this post]
 
In reply to a post by Zarjaz:
and Shiplake down near Henley-on-Thames,

An area I know well ...... cab 1, 2 or the newbie one up at the cross roads ?

Exchange WARGRAVE is served by Cabinet 1 smile

Edited by Jez_ (Fri 28-Apr-17 13:36:52)

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