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Standard User darrellr
(member) Sun 25-Dec-16 09:38:50
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Recovery profile


[link to this post]
 
I have had my house re-built from the ground up over the last 5 months and due to the builders desire for broadband to get a (wifi) phoe signal the router was on most of the time. Obviously during the first/second fix period there was a lot of on/off events and my rate dropped from 74 mbps to 20!

After 5 days of no events it recovered to 22400 and then the next day (yesterday) to 25000. This morning there was another forced change but no rate change (I suspect INP improved).

Is there a set recovery process? I'm assuming it will recover daily from now on.

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)
Standard User MHC
(sensei) Sun 25-Dec-16 10:19:45
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Re: Recovery profile


[re: darrellr] [link to this post]
 
In reply to a post by darrellr:
Is there a set recovery process? I'm assuming it will recover daily from now on.


WAIT and TIME


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

M H C


taurus excreta cerebrum vincit
Standard User ukhardy07
(knowledge is power) Sun 25-Dec-16 10:27:50
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Re: Recovery profile


[re: darrellr] [link to this post]
 
That speed change seems drastic and outside DLMs usual...

Do you have line stats?


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Standard User MHC
(sensei) Sun 25-Dec-16 10:57:44
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Re: Recovery profile


[re: ukhardy07] [link to this post]
 
May sound drastic but with builders there the disconnects, as suggested, may have been frequent however what is more likely is that the RFI/EMI from the tools will have driven a lot of disconnects and a very high noise floor at times.


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

M H C


taurus excreta cerebrum vincit
Standard User darrellr
(member) Sun 25-Dec-16 11:43:01
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Re: Recovery profile


[re: MHC] [link to this post]
 
smile

I know it will take time and I'm chilled about it. I assume the algorithm in the DSLAM will be fixed and it will follow a pattern to return my line to full speed.

If it isn't known I'll update this post with my experience as it recovers

Line stats:

DSL synchronization status: Up
Connection status: Showtime
Upstream line rate (kbit/s): 7200
Downstream line rate (kbit/s): 25000
Maximum upstream rate (kbit/s): 32027
Maximum downstream rate (kbit/s): 83480
Upstream noise safety coefficient (dB): 25.8
Downstream noise safety coefficient (dB): 22.8
Upstream interleave depth: 0
Downstream interleave depth: 0
Line standard: VDSL
Upstream line attenuation (dB): 17.6
Downstream line attenuation (dB): 8.9
Upstream output power (dBm): 4.6
Downstream output power (dBm): 12.6
Channel type: None
DSL up-time: 0 days 3 hours 59 minutes 59 seconds

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)
Standard User ukhardy07
(knowledge is power) Sun 25-Dec-16 14:01:58
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Re: Recovery profile


[re: darrellr] [link to this post]
 
Yeah it'll return to normal soon enough... The crazy thing is most homeowners do not even notice when their connection drops like this, if they are online and can get on instagram and stream netflix they are smiling along.
Standard User WWWombat
(knowledge is power) Sun 25-Dec-16 21:23:07
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Re: Recovery profile


[re: darrellr] [link to this post]
 
6 months ago, DLM was being *terrible*: it banded things too easily, and was really bad at recovering from banding. It would stick and stall at artificially low speeds, and never recover properly.

I've not seen many signs recently to suggest that this has either worsened or improved.
Standard User RobertoS
(elder) Mon 26-Dec-16 00:32:53
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Re: Recovery profile


[re: WWWombat] [link to this post]
 
Long story on banding changes.

A few months ago I found I was apparently banded at 60,000Kbps, a speed that strangely I had never reached until that happened. I have two HG612s. The one in use at the time was the one that hit the 60,000 through several re-sync's over the weeks. The Max attainable always a few hundred Kbps below that.

In late October or early in November I put the other one on just to test it and my spare 582n router still worked, so I could lend them to someone. This sync'ed in the mid 5700s with Max attainable a bit higher.

I decided to experiment with the ZyXel modem router from AA, which they had configured in router mode to be fed by the HG 612, to get the IPv6 working. It hadn't done from Day 1 as far as I know.

Over the next two or three weeks I tried that in modem router mode, giving 59999Kbps sync and Max attainable around the very high 69,000+Kbps. The IPv6 was unstable so I then substituted an HG612 feeding my ASUS RT-N66U which I knew handled IPv6 from my time with Plusnet.

Over this period my banding dropped to 55,000Kbps frown.

I then replaced the HG612 with a Draytek Vigor 130 modem hoping to help remove the banding. Feeding the ZyXel back in its original configuration. It provided IPv6 for a few hours then fell back to IPv4. Banding fell to 49,000Kbps.

I then obtained a Billion 8800NL R2 and installed it in modem router mode on Wednesday 17 Dec evening after four days of the Draytek. It sync'ed at the 48,999Kbps expected, with attainable at 67,000+Kbps. However I had to reboot it two or three times that evening to get IPv6 working properly.

10am Thursday 18 Dec DLM dropped the banding to 44,000Kbps frown. I hoped that was because of my continued messing around, and resigned myself to several weeks at that speed.

4:42am on Saturday 17 Dec it jumped back up to 55,000Kbps! Been there ever since. I now have to wait and see if and when it puts it back up to 60,000Kbps or even removes it altogether. Max attainable in the 67,000s.

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 54999/16208Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User darrellr
(member) Mon 26-Dec-16 09:45:27
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Re: Recovery profile


[re: darrellr] [link to this post]
 
end of disruption 17th December 20,000/4999

23rd December 09:00 resync to 22400/5999
24th December 08:40 resync to 25000/7240
25th December 07:45 resync (G.INP reduction?)
26th December 09:12 resync to 27400/8496

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)

Edited by darrellr (Mon 26-Dec-16 09:58:13)

Standard User 69bertie
(member) Mon 26-Dec-16 10:31:20
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Re: Recovery profile


[re: ukhardy07] [link to this post]
 
I would run the BT speed test It will tell you if you are outside your normal expected range. If it does, I would also contact your ISP and register a fault with them.

Certainly, despite what others have said (who I have much respect for) do not expect DLM to reset the line any day soon. The time it reset my line lower (June/July), it took getting on to 3 months to bring my line back up to what it is capable of. I then had another local power failure about a month ago. I'm back down to 64Mb, down from 76Mb. People say a single power loss of the modem will not get the attention of DLM. My experience says otherwise (or maybe we have an over active DLM around here). Personally, I wish they would turn the darn thing off.

Reporting a fault, at the very least, gets the attention of your ISP. If it is way outside the expected range, they will do the biz. Just don't stand back and expect things to improve. You'll be paying good money for a poor service for a long time.

Standard User ukhardy07
(knowledge is power) Mon 26-Dec-16 11:26:13
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Re: Recovery profile


[re: darrellr] [link to this post]
 
Yeah good point raised by most here...

When I said soon enough my experience is it took 2 months for DLM to release my line so do not expect it to happen overnight, but in time my line got better.
Standard User WWWombat
(knowledge is power) Mon 26-Dec-16 17:26:27
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Re: Recovery profile


[re: RobertoS] [link to this post]
 
Can you confirm the dates in the last few paragraphs? They don't make sense (eg 17th Dec was not a Wednesday).
Standard User RobertoS
(elder) Mon 26-Dec-16 17:51:21
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Re: Recovery profile


[re: WWWombat] [link to this post]
 
OOps blush!!

Too late to edit unfortunately.

Billion installed Wed 14 evening.
Final lowering of IP Banding 10am Thursday 15 December.
Jump to 55,000 banding correctly stated as 04:42 Saturday 17 Dec.

How I messed that up so badly I have no idea frown. Completely alcohol-free bar a small glass of fizz at lunchtime (because I was driving).

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 54999/16208Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WWWombat
(knowledge is power) Wed 28-Dec-16 02:34:28
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Re: Recovery profile


[re: RobertoS] [link to this post]
 
Yeah - quite typical symptoms. Over-zealous engagement of banding in the first place. Then a partial reduction in banding initially ... but one that never quite manages to complete.

This new behaviour seemed to coincide with the 2nd disastrous deployment of G.INP for ECI, but could have been a result of rework caused by the Assia patent agreement.

It seems strange that, just when they've deployed a decent workable item in the DLM toolkit (with G.INP, on Huawei at least), they set things back hugely with the banding behaviour.
Standard User darrellr
(member) Wed 28-Dec-16 08:21:50
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Re: Recovery profile


[re: darrellr] [link to this post]
 
23rd December 09:00 resync to 22400/5999
24th December 08:40 resync to 25000/7240
25th December 07:45 resync (G.INP reduction?)
26th December 09:12 resync to 27400/8496


28th December 07:29 resync to 29999/9999

At this rate (10 mbps pre week) I t will take me over a month to recover!!

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)

Edited by darrellr (Wed 28-Dec-16 09:49:15)

Standard User darrellr
(member) Fri 30-Dec-16 08:29:53
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Re: Recovery profile


[re: darrellr] [link to this post]
 
In reply to a post by darrellr:
23rd December 09:00 resync to 22400/5999
24th December 08:40 resync to 25000/7240
25th December 07:45 resync (G.INP reduction?)
26th December 09:12 resync to 27400/8496
27th December No resync
28th December 07:29 resync to 29999/9999
29th December No resync


30th December 06:58 resync to 32400/11999

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)

Edited by darrellr (Fri 30-Dec-16 08:52:04)

Standard User darrellr
(member) Wed 11-Jan-17 07:32:34
Print Post

Re: Recovery profile


[re: darrellr] [link to this post]
 
the recovery profile seems obvious from the stats so far. Within a week I should be back at 74-80 down/20 up.

23rd December 09:00 resync to 22400/5999
24th December 08:40 resync to 25000/7240
25th December 07:45 resync (G.INP reduction?)
26th December 09:12 resync to 27400/8496
27th December No resync
28th December 07:29 resync to 29999/9999
29th December No resync
30th December 06:58 resync to 32400/11999
31st December No resync
1st January 08:00 resync to 34999/14999
2nd January No resync
3rd January 06:46 resync to 40000/16999
4th January No resync
5th January 12:30 manual reboot - resync to 44000/19000
6th January No resync
7th January 04:56 resync to 49000/19999
8th January No resync
9th January 06:48 resync to 55000/19999
10th January No resync
11th January 06:54 resync to 60000/19999

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)
Standard User WWWombat
(knowledge is power) Wed 11-Jan-17 17:16:23
Print Post

Re: Recovery profile


[re: darrellr] [link to this post]
 
Good to see things happening so far. Fingers' crossed for the remainder.

What are your current line stats?
Standard User MHC
(sensei) Wed 11-Jan-17 17:39:39
Print Post

Re: Recovery profile


[re: darrellr] [link to this post]
 
It seems to be following the process I suggested in my earlier post: http://forums.thinkbroadband.com/fibre/t/4522571-re-...

You may see a couple more 5Mbps increments and then possibly a few smaller ones as you get close to the max achievable figure - it will be interesting to see what actually happens.

What is your modem saying for SNR and Max Achievable?


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

M H C


taurus excreta cerebrum vincit
Standard User darrellr
(member) Wed 11-Jan-17 22:44:15
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Re: Recovery profile


[re: MHC] [link to this post]
 
Maximum upstream rate (kbit/s): 31613
Maximum downstream rate (kbit/s) 80268
Upstream noise safety coefficient (dB): 15.6
Downstream noise safety coefficient (dB): 11.4

NB. Max achievable dropped from 83,400 to 80,300 around new years day. I assume that means crosstalk

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)

Edited by darrellr (Wed 11-Jan-17 22:48:51)

Standard User WWWombat
(knowledge is power) Thu 12-Jan-17 19:24:04
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Re: Recovery profile


[re: darrellr] [link to this post]
 
The max achievable is a theoretical value, extrapolated by the modem from current conditions.

It could be that another subscriber activated, added crosstalk, and you saw the effect.

It is also possible that, as the banding has reduced, the extrapolation process comes up with a different answer.
Standard User MHC
(sensei) Fri 13-Jan-17 08:45:04
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Re: Recovery profile


[re: darrellr] [link to this post]
 
Along with WWW's comment, there could be some additional external noise from a device in your house or that of a neighbour.


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

M H C


taurus excreta cerebrum vincit
Standard User WWWombat
(knowledge is power) Mon 23-Jan-17 14:26:55
Print Post

Re: Recovery profile


[re: darrellr] [link to this post]
 
In reply to a post by darrellr:
Within a week I should be back at 74-80 down/20 up.

23rd December 09:00 resync to 22400/5999
...
9th January 06:48 resync to 55000/19999
10th January No resync
11th January 06:54 resync to 60000/19999


Has there been any progress in the last couple of weeks?
Standard User darrellr
(member) Fri 24-Mar-17 11:34:47
Print Post

Re: Recovery profile


[re: WWWombat] [link to this post]
 
I had a small bump to 66999 mbs in mid- January and then it stuck pretty much. Twice the DSLAM forced a resync but no change in headline speed and I don't have stats for the G.INP on my router.

However, two days ago I suddenly saw a massive improvement in the noise figure and maximum attainable. I went from max attainable of 80-81 to 125! This morning my banding has increased back to the original figure of 74 mbps and I'm really hopeful that it will jump one last time to the full 80.

23rd December 09:00 resync to 22400/5999
24th December 08:40 resync to 25000/7240
25th December 07:45 resync (G.INP reduction?)
26th December 09:12 resync to 27400/8496
27th December No resync
28th December 07:29 resync to 29999/9999
29th December No resync
30th December 06:58 resync to 32400/11999
31st December No resync
1st January 08:00 resync to 34999/14999
2nd January No resync
3rd January 06:46 resync to 40000/16999
4th January No resync
5th January 12:30 manual reboot - resync to 44000/19000
6th January No resync
7th January 04:56 resync to 49000/19999
8th January No resync
9th January 06:48 resync to 55000/19999
10th January No resync
11th January 06:54 resync to 60000/19999
10th January No resync
11th January No resync
12th January No resync
13th January No resync
14th January 07:15 resync to 66999/19999
....
24th March 08:45 resync to 74000/19999 (SNR 20.4 db)

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)

Edited by darrellr (Fri 24-Mar-17 11:37:43)

Standard User WilliamGrimsley
(committed) Fri 24-Mar-17 11:41:26
Print Post

Re: Recovery profile


[re: darrellr] [link to this post]
 
It's great to know that banding is now being removed by the DLM. Also, it shows that the new DLM system has been introduced, it uses the 2 day stepped approach which was shown when my line was in the downstream SNR margin trial. smile

Edited by WilliamGrimsley (Fri 24-Mar-17 11:43:53)

Standard User WWWombat
(knowledge is power) Fri 24-Mar-17 12:35:30
Print Post

Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
It's great to know that banding is now being removed by the DLM.


I'll just keep my fingers' crossed that this changed is a generic improvement in DLM. The "stickiness" of banding has been a particularly poor trait of DLM for the last year, and we could do without it.

Lets hope the next 6Mbps disappears.
In reply to a post by WilliamGrimsley:
Also, it shows that the new DLM system has been introduced, it uses the 2 day stepped approach which was shown when my line was in the downstream SNR margin trial. smile


There's no evidence of the 5-4-3dB trial/live process here, yet.

A jump in attainable speed from 80 to 125Mbps is a change in SNRM of 12dB in theory (13dB, from 7.4dB to 20.4dB, in reality) - way, way, way beyond the scope of the 5-4-3dB trial.

In the absence of any other evidence, I would say it is more likely to indicate that vectoring was activated on the cabinet.
Standard User WilliamGrimsley
(committed) Fri 24-Mar-17 12:55:40
Print Post

Re: Recovery profile


[re: WWWombat] [link to this post]
 
In reply to a post by WWWombat:
I'll just keep my fingers' crossed that this changed is a generic improvement in DLM. The "stickiness" of banding has been a particularly poor trait of DLM for the last year, and we could do without it.

Haha, I bet you remember how annoyed I was! wink
In reply to a post by WWWombat:
There's no evidence of the 5-4-3dB trial/live process here, yet.

A jump in attainable speed from 80 to 125Mbps is a change in SNRM of 12dB in theory (13dB, from 7.4dB to 20.4dB, in reality) - way, way, way beyond the scope of the 5-4-3dB trial.

In the absence of any other evidence, I would say it is more likely to indicate that vectoring was activated on the cabinet.

I know that, I was just stating that the 2 day stepped approach is now being applied to removal of banding.

Edited by WilliamGrimsley (Fri 24-Mar-17 12:59:08)

Standard User darrellr
(member) Fri 24-Mar-17 13:51:51
Print Post

Re: Recovery profile


[re: WWWombat] [link to this post]
 
In reply to a post by WWWombat:
In the absence of any other evidence, I would say it is more likely to indicate that vectoring was activated on the cabinet.


I didn't realise that vectoring was 'live'. I thought it was a coming soon thing bundled with G.Fast.

NB. Is 125 mb/s the maximum theoretical for BT FTTC lines currently?

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)
Administrator MrSaffron
(staff) Fri 24-Mar-17 14:02:45
Print Post

Re: Recovery profile


[re: darrellr] [link to this post]
 
It is live on selected cabinets, where as on g.fast it is a fundamental part of the standard

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 24-Mar-17 22:09:04
Print Post

Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
It's great to know that banding is now being removed by the DLM. Also, it shows that the new DLM system has been introduced, it uses the 2 day stepped approach which was shown when my line was in the downstream SNR margin trial. smile
I see nothing to suggest any changes to DLM. His line was banded many months ago and is still banded now. It's always been the case that banding removes itself on some lines, partially removes itself on some lines, and just plain sticks on other lines.

The "2 day step" you're referring to that the OP details in the post above yours are actions from back in January. DLM has always acted in this way.

The only changes to DLM I've seen documented are the new lower dB SNRM targets. I recall a post within the past couple weeks saying something like OpenReach are aware of sticky banding and are working on a solution. I heard that about 18 months ago and the problem has only got worse since then.
Standard User WilliamGrimsley
(committed) Sat 25-Mar-17 10:52:09
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
There are changes that have been implemented with the new downstream SNR margin's. Oh, and yes I do know the downstream rate is still banded, but the amount of banding has been decreased by DLM, so something has changed. In the past, DLM wouldn't even decrease the amount of banding.

Edited by WilliamGrimsley (Sat 25-Mar-17 10:54:11)

Administrator MrSaffron
(staff) Sat 25-Mar-17 11:00:04
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Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
>In the past, DLM wouldn't even decrease the amount of banding.

So no-one ever had banded reduced or removed before the current changes?

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) Sat 25-Mar-17 11:05:55
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Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
Banding has always been changed incrementally.
Standard User WilliamGrimsley
(committed) Sat 25-Mar-17 11:22:02
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Re: Recovery profile


[re: MrSaffron] [link to this post]
 
Yes, especially recently! There was an update to the DLM which caused banding on lines to be stuck.

Edited by WilliamGrimsley (Sat 25-Mar-17 11:22:38)

Standard User WilliamGrimsley
(committed) Sat 25-Mar-17 11:22:52
Print Post

Re: Recovery profile


[re: lee111s] [link to this post]
 
No, not always.
Standard User lee111s
(experienced) Sat 25-Mar-17 11:33:59
Print Post

Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
What makes you so sure?

Edited by lee111s (Sat 25-Mar-17 11:34:20)

Standard User Chrysalis
(legend) Sat 25-Mar-17 12:01:10
Print Post

Re: Recovery profile


[re: WWWombat] [link to this post]
 
It may be a deliberate policy to prefer reduced sync speeds over the horrors of interleaving, if given the choice I would certainly pick banded over interleaving.

Of course on hauwei cabinets I would expect interleaving is now uncommon so banding may be overkill on hauwei lines.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User j0hn83
(member) Sat 25-Mar-17 12:02:31
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Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by j0hn83:
It's always been the case that banding removes itself on some lines, partially removes itself on some lines, and just plain sticks on other lines.
No idea where you get the idea that all banding sticks. Just because your line stuck doesn't mean everyone's does. You need to go back and read the post by darrellr that you commented on. He was discussing banding being removed in January.

Could you point me to something that shows other changes to DLM? A post somewhere official, something from OpenReach? The SNRM changes are the only changes documented.
Standard User RobertoS
(elder) Sat 25-Mar-17 12:31:54
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Re: Recovery profile


[re: Chrysalis] [link to this post]
 
G.INP on Huawei normally has interleaving at 8/1. Occasionally 12/1 or 16/1. Some modems can report n/4. However the "delay" parameter is zero.

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 65618/13914Kbps @ 600m. BQMs - IPv4 & IPv6
Standard User WilliamGrimsley
(committed) Sat 25-Mar-17 12:45:51
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
All you have to do is look in SIN 498, it's all in there.
Standard User Chrysalis
(legend) Sat 25-Mar-17 12:48:40
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Re: Recovery profile


[re: RobertoS] [link to this post]
 
yeah I meant legacy interleaving.

Sky Fibre Pro BQM - IPv4 BQM - IPv6
Standard User j0hn83
(member) Sat 25-Mar-17 13:03:25
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Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
In reply to a post by WilliamGrimsley:
All you have to do is look in SIN 498, it's all in there.

I think you need to read it again then. The only thing new related to DLM in SIN498 is the following
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.sinet.bt.com/sinet/sins/pdf/498v7p3.pdf

Edited by j0hn83 (Sat 25-Mar-17 13:03:50)

Standard User WilliamGrimsley
(committed) Sat 25-Mar-17 13:55:12
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
I know it only says that, but a new DLM system would've been introduced to allow for the new downstream SNR margin's! Anyway, let's enjoy this sunshine, I cba to deal with all of this rubbish!

Edited by WilliamGrimsley (Sat 25-Mar-17 13:56:08)

Standard User j0hn83
(member) Sat 25-Mar-17 14:18:13
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Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
That's just your assumption. It's much more likely the current DLM system was tweaked to accommodate the lower downstream SNRM target. It's a huge leap to assume the entire algorithm has been changed, the way banding is handled, and some new 2 day stepped approach added.

MDWS still shows DLM taking action daily when required. Your line may have dropped the SNRM target in 2 day stages, but on other lines we see 3 or 4 days between drops in target SNRM.

Unless you know for a fact something else has changed with DLM then suggesting such changes have occurred is likely to cause confusion for others.
Administrator MrSaffron
(staff) Sat 25-Mar-17 15:46:52
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
I guess we'll have to disagree with the other poster, as while some lines have been seen to stick, others have been seen to have banding relent

Reading into specification documents information that is not there is a dangerous game to play and leads to urban myths perpetuating for many years potentially

The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User darrellr
(member) Sun 26-Mar-17 09:12:50
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Re: Recovery profile


[re: darrellr] [link to this post]
 
...and finally!!

08:37:03, 26 Mar.
DSL Link Up: Down Rate=79999Kbps, Up Rate=19999Kbps; SNR Margin Down=15.0dB, Up=15.6dB

23rd December 09:00 resync to 22400/5999
24th December 08:40 resync to 25000/7240
25th December 07:45 resync (G.INP reduction?)
26th December 09:12 resync to 27400/8496
27th December No resync
28th December 07:29 resync to 29999/9999
29th December No resync
30th December 06:58 resync to 32400/11999
31st December No resync
1st January 08:00 resync to 34999/14999
2nd January No resync
3rd January 06:46 resync to 40000/16999
4th January No resync
5th January 12:30 manual reboot - resync to 44000/19000
6th January No resync
7th January 04:56 resync to 49000/19999
8th January No resync
9th January 06:48 resync to 55000/19999
10th January No resync
11th January 06:54 resync to 60000/19999
10th January No resync
11th January No resync
12th January No resync
13th January No resync
14th January 07:15 resync to 66999/19999
....
24th March 08:17 resync to 74000/19999 (SNR 20.4 db)
26th March 08:37 resync to 79999/19999

Current stats

6.Data Rate:19999 / 79999
7.Maximum Data Rate:31629 / 124412
8.Noise Margin:15.6 / 18.0
9.Line Attenuation:15.9 / 13.5

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)
Standard User Zarjaz
(eat-sleep-adslguide) Sun 26-Mar-17 09:19:43
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Re: Recovery profile


[re: darrellr] [link to this post]
 
How comes the attenuation in those stats doesn't match that in your sig ?

Standard User darrellr
(member) Sun 26-Mar-17 09:56:26
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Re: Recovery profile


[re: Zarjaz] [link to this post]
 
The attenuation seems to be measured differently on the BT router compared to the original talktalk one

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)
Standard User WilliamGrimsley
(committed) Sun 26-Mar-17 11:11:17
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
See, I told ya! His downstream rate isn't banded now! wink
Standard User j0hn83
(member) Sun 26-Mar-17 14:17:17
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Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
You told me what exactly?
In reply to a post by j0hn83:
It's always been the case that banding removes itself on some lines, partially removes itself on some lines, and just plain sticks on other lines.

Banding has ALWAYS removed itself in stages on most lines. It's only a small number of lines where banding sticks permanently. The OP's banding has been slowly decreasing for months.

I don't know where you got the idea that all banding is permanent. Your banding was so bad because you did something stupid that made DLM think your line was very broken.
Standard User WilliamGrimsley
(committed) Sun 26-Mar-17 17:47:08
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
I didn't do anything stupid! I was doing something totally unrelated which caused that to happen! You're very wrong... Also, where did I say all banding was permanent? Please stop accusing me of things without evidence!

Edited by WilliamGrimsley (Sun 26-Mar-17 17:47:46)

Standard User j0hn83
(member) Sun 26-Mar-17 18:25:21
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Re: Recovery profile


[re: WilliamGrimsley] [link to this post]
 
You deliberately removed/reconnected the DSL cable on your modem dozens of times "to see what DLM would do". Well it banded your line. You may not think that's stupid, I'm sure most would disagree.

Evidence? http://forum.kitz.co.uk/index.php/topic,16863

Enough said.
Standard User WilliamGrimsley
(committed) Sun 26-Mar-17 18:28:47
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
Exactly, I did that for testing purposes for my own knowledge! You don't get anywhere without testing! So, I didn't think it was stupid and tbh it was a good thing, because it allowed an Openreach engineer to see what was going on with this banding problem lots of people are facing and he checked the quality of my line pair!

Edited by WilliamGrimsley (Sun 26-Mar-17 18:29:55)

Standard User 69bertie
(member) Sun 26-Mar-17 19:10:38
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Re: Recovery profile


[re: j0hn83] [link to this post]
 
In reply to a post by j0hn83:
It's only a small number of lines where banding sticks permanently. The OP's banding has been slowly decreasing for months.

I don't know where you got the idea that all banding is permanent. Your banding was so bad because you did something stupid that made DLM think your line was very broken.

You'd think DLM was the holy grail of good software writing. If DLM cannot tell the difference between unplugging a line and a failing connection (varies) then it really should be slung in to the bin. In my case I lost 10mb/s last year (had to unplug the modem). Yes, it has 'slowly' been recovering such that it was back to 64.4 after nearly 6 months!. A far cry from the 78mb I had.

This weekend I thought I'd do something equally stupid, I changed the modem to get some stats. Weee. lost another 10 mb/s, such I'm now plumbing the depths of 50mb/s . And this is only ONE disconnection again. And my limited stats show I have a line length of 250m with a SNR of 5db on upstream and 5db downstream. BT own check shows 53.13 Mbps Max Achievable Speed.

I'm not expecting any real improvement via DLM, such I have raised a ticket with Plusnet because OR system clearly sucks.

Standard User WilliamGrimsley
(committed) Sun 26-Mar-17 19:33:53
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Re: Recovery profile


[re: 69bertie] [link to this post]
 
I agree! As much as I think DLM is beneficial, it's also a real nuisance. The EU should be able to ask their ISP to change DLM settings. But, I would recommend that ISP's don't advertise this as lots of people will start fiddling with DLM and then well it gets tricky...

Edited by WilliamGrimsley (Sun 26-Mar-17 19:35:33)

Standard User WWWombat
(knowledge is power) Mon 27-Mar-17 15:03:33
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Re: Recovery profile


[re: MrSaffron] [link to this post]
 
In reply to a post by j0hn83:
That's just your assumption. It's much more likely the current DLM system was tweaked to accommodate the lower downstream SNRM target. It's a huge leap to assume the entire algorithm has been changed, the way banding is handled, and some new 2 day stepped approach added.


I agree with you here, to a reasonable degree. But I also agree with Mr Saffron:

In reply to a post by MrSaffron:
Reading into specification documents information that is not there is a dangerous game to play and leads to urban myths perpetuating for many years potentially


My observations over the last few years suggest that BT have made rather large changes to the DLM algorithm - particularly over the last 3 years - and not just small tweaks. Those changes have then been introduced alongside each of the attempts at G.INP, but I strongly suspect that major changes have been brought in as a result of the Assia patent row.

We have certainly seen changes in the way that DLM resets occur and, alongside, the nature of banding. Banding is more likely to be introduced on a line than 5 years ago, and less likely to be removed. It is also more likely to survive a DLM reset.

But whenever DLM was going to reduce or remove banding (if ever), then it would work in a stepwise manner. In early days, it would tend to follow a small subset of speed steps, but has more recently changed to steps of 2.5Mbps (or alternate between 2.4 and 2.6Mbps). It still appears to be stepped.

With a new attempt to rollout G.INP again, and a parallel rollout of the 5-4-3dB trial, I'm expecting the pattern of the last 3 years to be repeated: that the nature of DLM changes markedly again.

In reply to a post by j0hn83:
Unless you know for a fact something else has changed with DLM then suggesting such changes have occurred is likely to cause confusion for others.


Absolutely.

DLM is, at best, an unknown quantity. And we can expect it to be in the midst of a change in nature again.

Making a definitive, unqualified statement about DLM is probably unwise.
Standard User WWWombat
(knowledge is power) Mon 27-Mar-17 15:12:21
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Re: Recovery profile


[re: 69bertie] [link to this post]
 
In reply to a post by 69bertie:
This weekend I thought I'd do something equally stupid, I changed the modem to get some stats.


My observations of recent DLM behaviour suggests that, nowadays, it is trying to keep track of whether the modem on a line is capable of supporting G.INP well, and to adjust the line settings quickly in response.

I imagine the aim is to ensure that swapping to a bad modem never renders the line totally u/s. A problem that has been seen in the G.INP rollouts.

Swapping modem is therefore an event that DLM might jump on extremely quickly, rather than just waiting to count the error rates.

Its a theory I haven't discounted yet, anyway.
Standard User darrellr
(member) Mon 27-Mar-17 16:18:17
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Re: Recovery profile


[re: darrellr] [link to this post]
 
Oddly enough I had a DSLAM initiated retrain again this morning and the stats say I gained 1 kbit/s more upstream! I assume further G.INP changes but can't see that on a BT HH5

New sync is 79999/20000

I assume all this activity (my 'unbanding') is a consequence of the switch on of vectoring at the Cab? Perhaps I'm on a new training period.

TalkTalk Business Fibre Broadband
(74 mbps, 9db attenuation, 7.4db SNR, 300 metres from cab)

Edited by darrellr (Mon 27-Mar-17 16:38:12)

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