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Standard User andylong42
(learned) Thu 26-Apr-12 12:16:06
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New speeds upgrade question


[link to this post]
 
I currently get approx 23/6mb on Infinity. When I check my number on the BT checker, it is suggesting I should get 32/6. If I upgraded to Infinity 2 (or whatever they have called it), will this increase my current speeds or are the speeds only increased for the people getting close to 40Mb in the past? Or should I be getting 32Mb on my current package and I in fact need to investigate an issue?

I would rather not sign up for a further 18months if I can help it!

Many thanks

Andy
Administrator MrSaffron
(staff) Thu 26-Apr-12 12:18:31
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Re: New speeds upgrade question


[re: andylong42] [link to this post]
 
The profile 17a has been running for some time, so my understanding is that you will only really go faster if already synced at the maximum speeds.

Andrew Ferguson, [email protected]
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
ISP Representative Adsl24
(isp) Thu 26-Apr-12 16:13:32
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Re: New speeds upgrade question


[re: andylong42] [link to this post]
 
No point as MrSaffron says. Only people who are getting the full 40Mb at present should think about upgrading, as if your line cannot SYNC at 40Mb already it can't go any higher by upgrading to 80, as it's already at the max it can sustain...

James
Technical Director, ADSL24

We supply ADSL, ADSL2+, LLU and FTTC VDSL2 services as well as cheap line rental and bundle deals!
Visit our website for the latest offers.
The above post has been made by an ISP REPRESENTATIVE (although not necessarily the ISP being discussed in the post).


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Standard User stephen79
(fountain of knowledge) Thu 26-Apr-12 19:43:21
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Re: New speeds upgrade question


[re: Adsl24] [link to this post]
 
Would he get any more from the upload?

BTInternet
ISP Representative Adsl24
(isp) Thu 26-Apr-12 20:18:17
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Re: New speeds upgrade question


[re: stephen79] [link to this post]
 
Same applies... if you are not SYNCing at 40Mb down, 10Mb up at present, you can't get any more by going to the 80/20 service.

James
Technical Director, ADSL24

We supply ADSL, ADSL2+, LLU and FTTC VDSL2 services as well as cheap line rental and bundle deals!
Visit our website for the latest offers.
The above post has been made by an ISP REPRESENTATIVE (although not necessarily the ISP being discussed in the post).
Standard User andylong42
(learned) Mon 30-Apr-12 15:30:57
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Re: New speeds upgrade question


[re: MrSaffron] [link to this post]
 
I have done a test on the speedtester.bt.com site and it is showing my profile to be 23.7Mbps. Is there anything I can do to up this as the online estimate is nearly 10Mbps higher?
ISP Representative Adsl24
(isp) Mon 30-Apr-12 16:08:32
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Re: New speeds upgrade question


[re: andylong42] [link to this post]
 
The online checker is just an estimate. Some people are able to get more, and some less, but it all depends on your individual line I am afraid.

BT won't do much or treat it as a "fault", so it's a difficult one.

Do you have problems with the service dropping out or is it stable?

James
Technical Director, ADSL24

We supply ADSL, ADSL2+, LLU and FTTC VDSL2 services as well as cheap line rental and bundle deals!
Visit our website for the latest offers.
The above post has been made by an ISP REPRESENTATIVE (although not necessarily the ISP being discussed in the post).
Standard User andylong42
(learned) Mon 30-Apr-12 16:10:26
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Re: New speeds upgrade question


[re: Adsl24] [link to this post]
 
It is fairly stable. I am just curious how plusnet, who use the same checker apparently, will guarantee the speed will be within 1Mb of the estimate - I am currently 9Mb below it!
ISP Representative Adsl24
(isp) Mon 30-Apr-12 16:15:07
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Re: New speeds upgrade question


[re: andylong42] [link to this post]
 
By saying they "guarantee it" does not mean they can offer it. 99% of the time a line will achieve more than the checker estimate but not in your case.

So by saying they will guarantee it will just mean you have a get out clause if you don't get within 1Mb of the estimate.

No ISP you move to can improve what your line can SYNC at on FTTC, they are all the same physical connection to the cabinet, so it's not an ISP problem as such.

HTH

James
Technical Director, ADSL24

We supply ADSL, ADSL2+, LLU and FTTC VDSL2 services as well as cheap line rental and bundle deals!
Visit our website for the latest offers.
The above post has been made by an ISP REPRESENTATIVE (although not necessarily the ISP being discussed in the post).
Standard User RobertoS
(sensei) Mon 30-Apr-12 16:23:05
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Re: New speeds upgrade question


[re: Adsl24] [link to this post]
 
Is there any possibility there is a banded profile at 25Mbps sync James, and that somehow he has been put on it? I don't know what the bands are, but 23.7Mbps IP Profile looks suspiciously like a 25Mbps sync.

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
ISP Representative Adsl24
(isp) Mon 30-Apr-12 16:31:17
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Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
Entirely possible, would need his ISP to run a diagnostic check to see if its been banded.

James
Technical Director, ADSL24

We supply ADSL, ADSL2+, LLU and FTTC VDSL2 services as well as cheap line rental and bundle deals!
Visit our website for the latest offers.
The above post has been made by an ISP REPRESENTATIVE (although not necessarily the ISP being discussed in the post).
Standard User Bald_Eagle1
(committed) Mon 30-Apr-12 16:43:55
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Re: New speeds upgrade question


[re: andylong42] [link to this post]
 
In reply to a post by andylong42:
Or should I be getting 32Mb on my current package and I in fact need to investigate an issue?


A number of factors will be affecting the speeds you can currently achieve.

Not least is the distance from the fibre cabinet.
Do you have a rough idea what that distance is?

How often the connection re-syncs can also have a major effect on how DLM sets sync speeds, as can cumulative error counts, copper or aluminium cabling, time between errors, noise interference, crosstalk etc...........

I am situated "up to" 1000m from my cabinet, currently in sync at 29.6Mb & have occasionally synced at up to 35Mb & as low as 7Mb when my connection had major physical issues.

FWIW, My original estimate was 14.6Mb (original 8c profile) & I achieved a stable 35Mb sync speed for almost a full month.
Profile 17a was introduced in October 2011 on my connection & my estimate went up to 24Mb.
My estimate has been 30Mb for the last couple of months.

My ISP put me on the 80/20 trial just as an experiment to see if cabinet output power could be automatically increased for the higher frequencies that MIGHT have improved sync speeds.

This experiment proved just one thing:-
Sync speeds were not improved at all frown & I am now back on the 40Mb service, at my request.

HTH.
Standard User Bald_Eagle1
(committed) Mon 30-Apr-12 16:46:26
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Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
As IP Profile is 96.79% of sync speed for FTTC, a 25Mb sync speed should give an IP Profile of 24.2Mb (approx)
Standard User RobertoS
(sensei) Mon 30-Apr-12 16:50:27
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Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
Thanks. I couldn't remember the percentage. Though I suppose 38717/40000 gives a clue tongue smile. Knocks my 25Mbps sync idea on the head, but may still be worth the OP getting it checked.

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Standard User andylong42
(learned) Mon 30-Apr-12 16:51:03
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Re: New speeds upgrade question


[re: Adsl24] [link to this post]
 
Is this a simple thing to ask for, or would it be a typically life-shortening experience trying to explain to BT?

Also, does anyone else think the upgrade to Infinity 2 page is very misleading? It says "upgrade to higher speed for free" with a big button to press. What would be my legal standing if I did this and got no increase, but still had a new 18month contract?
Administrator MrSaffron
(staff) Mon 30-Apr-12 17:01:09
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Re: New speeds upgrade question


[re: andylong42] [link to this post]
 
If the speed was even just 0.1Mbps faster for upload or download, then they could say you got a higher speed.

All you stand to win is a waiver for the need for a new 18 month contract

Andrew Ferguson, [email protected]
www.thinkbroadband.com - formerly known as ADSLguide.org.uk
The author of the above post is a thinkbroadband staff member. It may not constitute an official statement on behalf of thinkbroadband.
Standard User qasdfdsaq
(newbie) Mon 30-Apr-12 18:28:59
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Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
Thanks. I couldn't remember the percentage. Though I suppose 38717/40000 gives a clue tongue smile. Knocks my 25Mbps sync idea on the head, but may still be worth the OP getting it checked.

Doesn't mean it's not a banded profile though. The bands don't seem to fall on an exact full megabit number. After some cockups on my line, I'm on a banded profile and capped at 47855 down, 16993 up. Other times I've been capped at 60181/19000 and 61081/18999 (sic).
Standard User Bald_Eagle1
(committed) Mon 30-Apr-12 22:29:36
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Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
Doesn't mean it's not a banded profile though. The bands don't seem to fall on an exact full megabit number. After some cockups on my line, I'm on a banded profile and capped at 47855 down, 16993 up. Other times I've been capped at 60181/19000 and 61081/18999 (sic).


Are those sync speeds or IP Profile speeds that you quote?

My connection has been banded on & off due to various issues over the months.
When banded, DLM has set the Downstream sync speed at values such as 24999, 27399, 24699, 32399, 14999, 7999, 12999 & so on.

Upstream sync speed has never been banded (apart from when I had a capped 2Mb Upstream service, when US sync speed was always 1999 k).


Working it backward, a sync speed of 24499 k would give an IP profile of approx 23713 k & a maximum throughput of approx 23001k (so maybe the OP is on a sync speed profile banded at 24499k)?

Edited by Bald_Eagle1 (Mon 30-Apr-12 22:39:14)

Standard User qasdfdsaq
(newbie) Mon 30-Apr-12 23:06:37
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Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
Sync speeds. My current IP profile is 46.32, on a downstream sync speed of 47855. I've definitely been banded on upstream as well, over the past few days my US sync rate has been 19000, 18000, 17000, and 16993, while normally it's 20000 with >31000 attainable.
Standard User RobertoS
(sensei) Mon 30-Apr-12 23:15:42
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Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
I think I'm right in saying that if the OR DLM applies banding, it is quite likely to remove it automatically after a while?

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Standard User Bald_Eagle1
(committed) Tue 01-May-12 06:10:15
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Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
I think I'm right in saying that if the OR DLM applies banding, it is quite likely to remove it automatically after a while?


I think that's the theory. It certainly seems to be the case for day-to-day re-syncs.
However, if the banding was applied in definite steps such as 24999 k 29999 k due to serious problems requiring physical engineering repairs etc. it appears to take many, many days or even weeks before DLM increases sync speeds.

When that is the case (a "stuck" DLM profile) it can be reset/recalculated remotely, but currently this can only be requested via an engineer's visit.

I have had engineers carry out repair work who REFUSED to request a DLM reset & I have been stuck at low & rigid sync speeds for more than a couple of weeks at a time while I awaited a different engineer to arrive who did nothing but request DLM to be reset.
Standard User paul1360
(member) Tue 01-May-12 08:42:05
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Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
OP,
If you have run a BT speed test what was your IP profile???
If I understand what is being said here is that if you don't get the Full 40/10Mb speeds then you will not see speeds near the 80/20Mb profile??????? If I'm reading this wrong sorry.
I was getting 36-37Mb / 7-8Mb and am now getting 76/17-18Mb stable speed now after the uplift, At first they were lower but have picked up over the last several days, I'm about 140m+ from my cab.
iechyd da

Standard User RobertoS
(sensei) Tue 01-May-12 10:08:28
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Re: New speeds upgrade question


[re: paul1360] [link to this post]
 
In reply to a post by paul1360:
OP,
If you have run a BT speed test what was your IP profile???
If I understand what is being said here is that if you don't get the Full 40/10Mb speeds then you will not see speeds near the 80/20Mb profile??????? If I'm reading this wrong sorry.
I was getting 36-37Mb / 7-8Mb and am now getting 76/17-18Mb stable speed now after the uplift, At first they were lower but have picked up over the last several days, I'm about 140m+ from my cab.
iechyd da
I think you are confusing the sync speed with the IP Profile and/or speed test results. A 40Mbps sync has a 38.72 IP profile, delivering at full pelt the 36-37Mbps you quote on a speed test.

What is being said is that if you did not get 40Mbps sync on the 40Mbps product then you would get not get an increase by upgrading to the 80/20 one.

You were achieving the full 40/10 speeds.

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Standard User paul1360
(member) Tue 01-May-12 10:34:24
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Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
RobertoS,
Ok lol story of my life of late getting confused and yes I was reading it wrong >>>>>giving himself a good kicking.
Best if I keep my mouth zipped shut.
iechyd da

Standard User qasdfdsaq
(regular) Sun 06-May-12 01:43:15
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Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
After only one resync in 7 days, DLM thought it appropriate to decrease my downstream speed even further, and now has me capped at 47146 down, 18998 up (1mbps increase in UL). While it's clearly limiting me, the caps I have seem nothing like the ones you got.

Some people have mentioned 10-15 days, well after 7 it's just getting worse.
Standard User Bald_Eagle1
(committed) Sun 06-May-12 07:48:59
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Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
After only one resync in 7 days, DLM thought it appropriate to decrease my downstream speed even further, and now has me capped at 47146 down, 18998 up (1mbps increase in UL). While it's clearly limiting me, the caps I have seem nothing like the ones you got.


47146 does not look like a banded speed cap.
It does look as though it was the best speed the connection could manage at the time it resynced.

You may have a connection with many errors of various types.
Interleaving, delay & impulse noise protection may be set at very high levels.
It is possible your connection suffers from bursts of REIN (interference).
If there are many users in the vicinity, it could even suffer badly from crosstalk.

Of course, it could be that the D-Side cable from the cabinet is full of dodgy corroded joints, aluminium sections, water in the cables, damaged cables etc. etc. etc.

Did the resync occur on its own (on the fly) or did you initiate it?
Standard User qasdfdsaq
(regular) Sun 06-May-12 11:12:06
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Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
In reply to a post by Bald_Eagle1:
In reply to a post by qasdfdsaq:
After only one resync in 7 days, DLM thought it appropriate to decrease my downstream speed even further, and now has me capped at 47146 down, 18998 up (1mbps increase in UL). While it's clearly limiting me, the caps I have seem nothing like the ones you got.


47146 does not look like a banded speed cap.
It does look as though it was the best speed the connection could manage at the time it resynced.

You may have a connection with many errors of various types.
Interleaving, delay & impulse noise protection may be set at very high levels.
It is possible your connection suffers from bursts of REIN (interference).
If there are many users in the vicinity, it could even suffer badly from crosstalk.

Of course, it could be that the D-Side cable from the cabinet is full of dodgy corroded joints, aluminium sections, water in the cables, damaged cables etc. etc. etc.

Did the resync occur on its own (on the fly) or did you initiate it?

You'd think so at first, but that's not the case. It really is a DLM imposed cap. In fact, I thought so too, so I rebooted the modem a couple times but it always resynced at exactly 47146.

Initially, the resync occurred by itself at about 6am. Stats showed there were about 16 FEC and CRC errors at the time, in total, accumulated over 5 days. SNR margin was 13.5 and attainable rate over 92000.

20 hours later I forced a resync myself, and came back with exactly the same sync rate - SNR margin was 14.2 at the time, attainable rate ~94100. So it's not a static (high) SNRM, nor is it the max the line could do - it was stable (no resyncs) at 79,999 for a few weeks before I moved the cables excessively. xdslcmd info showed zero OHFErr and zero RSUnCorr, GUI showed zero FEC or HEC errors just before I resynced.

Right now after another 10 hours uptime, the GUI's showing zero CRC, FEC or HEC errors:

Attainable rate (kbit/s) 94076 32050
SNR margin (dB) 14.1 9.5
Line attenuation (dB) 0 0
Output power (dBmV) 12.6 5.7

I do a full reboot of the modem and it's still at exactly 47146.

Downstream Upstream Downstream Upstream
Line rate (kbit/s) 47146 18998 0 0
CRC errors 0 0 0 0
FEC errors 0 0 0 0
HEC errors 0 0 0 0

I know it does suffer badly from crosstalk - it's 90m from cabinet and should have an attainable rate well over 100 - but full modem stats here show quite high noise across the spectrum. I've done some investigation, and reducing attenuation simply increases the noise by the same amount, while shielded cable makes no difference - so I conclude it's crosstalk as it's coming from further up the line than my property and is surprisingly flat across the whole 30a spectrum.

Another trick I have up my sleeve is picking up the phone, which instantly reduces attainable rate by about 5mbps as follows:

Attainable rate (kbit/s) 89516 26890
SNR margin (dB) 12.9 8.4
Line attenuation (dB) 0 0
Output power (dBmV) 12.6 5.7

However, once again, a forced resync comes back again at exactly 47146/18998:

Downstream Upstream Downstream Upstream
Line rate (kbit/s) 47146 18998 0 0
CRC errors 0 0 0 0
FEC errors 0 0 0 0
HEC errors 0 0 0 0

(So exactly the same behaviour as when it was previously stuck at 60181 for 7 days - aside from when DLM changes my line speed cap, my line hasn't had a single unexpected resync/loss of sync since it's been installed)

Edited by qasdfdsaq (Sun 06-May-12 11:14:28)

Standard User Bald_Eagle1
(committed) Mon 07-May-12 08:51:10
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Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
You'd think so at first, but that's not the case. It really is a DLM imposed cap. In fact, I thought so too, so I rebooted the modem a couple times but it always resynced at exactly 47146.

That's interesting & it can't be pure coincidence to achieve EXACTLY the same sync speed on rebooting the modem.

Initially, the resync occurred by itself at about 6am. Stats showed there were about 16 FEC and CRC errors at the time, in total, accumulated over 5 days. SNR margin was 13.5 and attainable rate over 92000.

Nothing really obvious then to have caused the resync.
Have you tried the ongoing stats that plot your connection stats minute by minute?
You may be able to see SNRM tailing off to zero (sometimes negative values) over a few minutes before the connection resyncs & puts SNRM back to usual levels.

I do a full reboot of the modem and it's still at exactly 47146.

Strange.

I know it does suffer badly from crosstalk - it's 90m from cabinet and should have an attainable rate well over 100 - but full modem stats here show quite high noise across the spectrum. I've done some investigation, and reducing attenuation simply increases the noise by the same amount, while shielded cable makes no difference - so I conclude it's crosstalk as it's coming from further up the line than my property and is surprisingly flat across the whole 30a spectrum.

I see from those stats that Interleaving depth (D) is quite high at 1686 DS & 527 US.
I imagine that Impulse Noise Protection (INP) & delay (delay) will also be quite high too.
INP & delay can be seen lower down the full Plink.log

How did you manage to reduce attenuation?
My connection suffers from really high attenuation that simply stops it syncing at anything higher than around 30 Mb.

Another trick I have up my sleeve is picking up the phone, which instantly reduces attainable rate by about 5mbps as follows:

Attainable rate (kbit/s) 89516 26890
SNR margin (dB) 12.9 8.4
Line attenuation (dB) 0 0
Output power (dBmV) 12.6 5.7

I occasionally see that phenomenon on my connection.
Attainable rates fluctuate in line with SNRM fluctuations.

I have seen SNRM dropping when dialling out to run the 17070 quiet line test etc.
My SNRM is usually only around 5dB or so, often dropping naturally to 3.5dB to 4dB overnight.
When the using the phone is especially bad, SNRM drops by 4dB or so which immediately forces the connection to resync (usually at a lower speed).

Dialling in to the phone sometimes causes SNRM to increase or lower.
Again, dialling in sometimes causes an immediate resync.

The last time dialling in caused a resync, the connection achieved a higher sync speed & then maintained stability for quite a few days, SNRM levels only dropping by 0.1dB or 0.2dB as should be expected.

It's almost as though the pulsed ringing tone voltages/current caused a dodgy connection somewhere in the D-Side cable to "fix itself".

Quiet line tests are always QUIET nowadays whenever I run them.

I have had many engineer visits due to my connection's instability & low(ish) speeds, "stuck" DLM profiles etc.

In attempts to permanently fix this particular phone issue, engineers have removed a double jumpered connection in the cabinet, replaced & rerouted my drop wire from the DP (approx 50m in length), replaced the master socket filtered faceplate, replaced just the filter pcb & replaced some slightly corroded cabinet jumper wires.

Each time, the connection seems to be fixed, but it usually only lasts for a few days.

More recently, I have noticed the phone issue appears to start as the weather changes to warm & dry periods for a few days.

April was supposedly one of the wettest & coldest on record.
It may be pure coincidence, but my connection was at its most stable during April.

The weather was quite warm & dry yesterday & my connection had resynced at only 23313 k at 20:12 while we were out last night.
My ongoing graphs show that SNRM had dropped from 4.5dB to -0.2dB (minus value) over around 1 hour, before causing the resync.

I tried the phone thing & noticed changes in SNRM levels while testing.

My connection resynced again at 29307 k at 07:02 this morning, while we were still in bed.
My ongoing logs do not show any particular issues for around that period.

Latest 24 hour ongoing stats here

Using the phone has gone back to only very insignificant changes in SNRM levels.
I'll see if that changes if the weather stays warm & dry for the next few days.

However, once again, a forced resync comes back again at exactly 47146/18998:

Downstream Upstream Downstream Upstream
Line rate (kbit/s) 47146 18998 0 0
CRC errors 0 0 0 0
FEC errors 0 0 0 0
HEC errors 0 0 0 0

Again, strange.


(So exactly the same behaviour as when it was previously stuck at 60181 for 7 days - aside from when DLM changes my line speed cap, my line hasn't had a single unexpected resync/loss of sync since it's been installed)


I wonder if your connection has started to develop an intermittent D-Side fault, possibly similar to mine?

One engineer in another forum has suggested that the plug in connection module at some DPs (known as a coffin lid DP due to its shape) can be a little unreliable. i.e. not always maintaining a solid connection on the relatively thin wires in use.
Apparently, a "fix" for this is to crimp some thicker wire to the thin wire & use the thicker wire for the actual plug in connection.

I wonder if Zarjaz and/or any other engineers would be able to comment on that as a "potential" cause of using the phone issues.

This is all ifs, buts & maybes & as these issues tend to be intermittent, it must be really hard for engineers to track them down as they may not be prevalent at the time of their visits.
Standard User qasdfdsaq
(regular) Mon 07-May-12 14:16:43
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
In reply to a post by Bald_Eagle1:
In reply to a post by qasdfdsaq:
You'd think so at first, but that's not the case. It really is a DLM imposed cap. In fact, I thought so too, so I rebooted the modem a couple times but it always resynced at exactly 47146.

That's interesting & it can't be pure coincidence to achieve EXACTLY the same sync speed on rebooting the modem.

That's my thinking. If I get the same exact sync speed on several different days, under several different conditions, then the only explanation I can think of is an artificial cap. Incidentally, 6am today right on schedule, DLM reset my line again. It's now increased my upstream again to 19842, and reduced downstream even further, to 47036.

Nothing really obvious then to have caused the resync.
Have you tried the ongoing stats that plot your connection stats minute by minute?
You may be able to see SNRM tailing off to zero (sometimes negative values) over a few minutes before the connection resyncs & puts SNRM back to usual levels.

I had considered it, but my PC uses a good 200watts at idle and I'm not inclined to leave it on 24/7. Also, the resyncs do show at almost exactly 6am on my TBB charts, which matches with what other people have observed to be the time that DLM normally does its adjustments.

How did you manage to reduce attenuation?

My connection suffers from really high attenuation that simply stops it syncing at anything higher than around 30 Mb.

I replaced all the wiring within my house - including between the master socket and the junction box - with Cat 6 shielded. It dropped ~1.5dB off the attentuation but made no difference in speeds, so I put the old BT cable back. I also used a shorter modem lead and wired it straight into the socket (the filtered IDCs behind the bottom plate) which also cut off about 0.3-0.5dB.

The last time dialling in caused a resync, the connection achieved a higher sync speed & then maintained stability for quite a few days, SNRM levels only dropping by 0.1dB or 0.2dB as should be expected.

It's almost as though the pulsed ringing tone voltages/current caused a dodgy connection somewhere in the D-Side cable to "fix itself".

Curious. Something I did too makes me think there's something else going on. My modem cable is wired into the faceplate directly, leaving the modem socket unused. If I plug in a 15m long ADSL extension cable into the socket - while the modem is still wired in - and just leave it dangling off like a long unfiltered telephone extension, my SNR margin drops to negative, attainable rate drops to 40mbps, and my line disconnects and resyncs. But when it resyncs, it resyncs at "full" (capped) 47mbps and attainable rate shows as 85mbps again - and it stays stable this way.

If I then disconnect the ADSL extension again, the same thing happens - even though theoretically it should increase SNR margin and attainable rate from 85 to 95, it causes a line drop and resync. So it seems like a change in line characteristics (e.g. impedance, capacitance or frequency binning) can cause the line to drop, even if available headroom is still way above (even double) what it's synced at.


The weather was quite warm & dry yesterday & my connection had resynced at only 23313 k at 20:12 while we were out last night.
My ongoing graphs show that SNRM had dropped from 4.5dB to -0.2dB (minus value) over around 1 hour, before causing the resync.

What's the maximum speed your line's ever synced at? Gradually dropping over an hour would be a perfect case for SRA, if only anyone would sort out deploying that around here...

I wonder if your connection has started to develop an intermittent D-Side fault, possibly similar to mine?

It all started when I moved the cabling and modem several times in a day, and tested at least a dozen different extension cables (as well as having accidentally shorted the wires a few times). I'm hoping I haven't caused a fault and it's just DLM being paranoid from my deliberate resets.

Y'know I kinda wish DLM could just be turned off completely sometimes. Your issues and my old Be/O2 line problem would all benefit. I'd rather have 1-2 minutes of downtime a day while my line repeatedly resyncs than be constantly at half speed for weeks on end...

One engineer in another forum has suggested that the plug in connection module at some DPs (known as a coffin lid DP due to its shape) can be a little unreliable. i.e. not always maintaining a solid connection on the relatively thin wires in use.
Apparently, a "fix" for this is to crimp some thicker wire to the thin wire & use the thicker wire for the actual plug in connection.

I wonder if Zarjaz and/or any other engineers would be able to comment on that as a "potential" cause of using the phone issues.

This is all ifs, buts & maybes & as these issues tend to be intermittent, it must be really hard for engineers to track them down as they may not be prevalent at the time of their visits.

My only recommendation here is - have you considered just getting a completely new, seperate BT line installed? If they can't fix your old line, and you're out of contract, I'd just get a second line, move the service over to that, and disconnect the old one. BT are doing free installation of new lines if you order online right now.
Standard User Bald_Eagle1
(committed) Mon 07-May-12 14:51:59
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
What's the maximum speed your line's ever synced at? Gradually dropping over an hour would be a perfect case for SRA, if only anyone would sort out deploying that around here...

When FTTC was installed last June (8c profile, but prior to access to unlocking firmware), sync speed must have been around 35Mb or so as I was actually downloading at up to 33Mb for almost a full month before everything started to go pear-shaped.

DLM was reset during a fairly recent engineer's visit (9th March). Sync speed was 35322 k for a short while before starting the usual downward journey.


I thought SRA was in place, hence "on the fly" resyncs that are so quick (16 seconds or so) that they do NOT initiate a new PPP session & therefore do NOT update the BT IP Profile/BRAS Rate.

My only recommendation here is - have you considered just getting a completely new, seperate BT line installed? If they can't fix your old line, and you're out of contract, I'd just get a second line, move the service over to that, and disconnect the old one. BT are doing free installation of new lines if you order online right now.

Yep, I have looked into that.
However, as spare pairs are available in the existing D-Side bundle, they would simply use those.
I have already had the D-Side pairs swapped in an effort to eliminate a single faulty pair.
My belief is that dodgy joints/connections are the root cause of my issues, perhaps only being noticed as my connection speed NEVER reaches the maximum for the capped 40Mb service, therfore my connection is already in a "delicate" condition.

It appears I may be the very last house on my STD code & have the option of a new line from a different exchange.
However, the closest fibre cab from that exchange is over 2km from my home!!!!!! frown
Standard User qasdfdsaq
(regular) Mon 07-May-12 15:53:21
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
In reply to a post by Bald_Eagle1:
When FTTC was installed last June (8c profile, but prior to access to unlocking firmware), sync speed must have been around 35Mb or so as I was actually downloading at up to 33Mb for almost a full month before everything started to go pear-shaped.

Shame - that suggests you should be getting well over 40 on 17a, or at least bang-on 40 on capped.

DLM was reset during a fairly recent engineer's visit (9th March). Sync speed was 35322 k for a short while before starting the usual downward journey.

That's odd - going from 8c to 17a should have made a significant difference.

I thought SRA was in place, hence "on the fly" resyncs that are so quick (16 seconds or so) that they do NOT initiate a new PPP session & therefore do NOT update the BT IP Profile/BRAS Rate.

Well, that depends what router you use - I've set mine to a custom PPP timeout of 60 seconds so I can manage a full modem reboot and still not initiate a new PPP session (primarily to keep my IP address for the TBB monitor).

A 16-second resync isn't SRA - with SRA in place, it doesn't go down to resync at all. It just seamlessly reduces your rate from one second to the next, hence the name. Course, that would totally break BTw's IP profiling system which is only why the rare LLU provider on ADSL2+ has tried it.

Yep, I have looked into that.
However, as spare pairs are available in the existing D-Side bundle, they would simply use those.
I have already had the D-Side pairs swapped in an effort to eliminate a single faulty pair.
My belief is that dodgy joints/connections are the root cause of my issues, perhaps only being noticed as my connection speed NEVER reaches the maximum for the capped 40Mb service, therfore my connection is already in a "delicate" condition.

It appears I may be the very last house on my STD code & have the option of a new line from a different exchange.
However, the closest fibre cab from that exchange is over 2km from my home!!!!!! frown

Shame then. As mentioned I'd expect if you were getting 35mbps on profile 8c then you should be hitting the 40mbps cap all the time on 17a. Have you got a full modem stats pic somewhere I can see?

Only other thing I can think of, if BT can't/won't fix your line - get a second line installed to someone else's home, whom you know has a good line, and pipe it over to yours via Ethernet?
Standard User elevator
(regular) Mon 07-May-12 16:05:43
Print Post

Re: New speeds upgrade question


[re: andylong42] [link to this post]
 
I used to get 32-35mbs upload and about 6-7mbs download. Since upgrade I get a a variable 55- 65mbs upload never less than 50mbs (so far) and a almost constant 10mbs up load.

My Broadband Speed Test

Edited by elevator (Mon 07-May-12 16:07:15)

Standard User Bald_Eagle1
(committed) Mon 07-May-12 16:17:40
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
Shame then. As mentioned I'd expect if you were getting 35mbps on profile 8c then you should be hitting the 40mbps cap all the time on 17a. Have you got a full modem stats pic somewhere I can see?


I thought that too (at first). Almost everyone else saw increases in DS speeds when 17a was introduced.

However, I think that attenuation is simply too high on my connection (due to distance and/or condition of the cables/joints) to achieve the full fat 40 Mb.


8c profile:-

Discovery Phase (Initial) Band Plan
US: (0,95) (696,1183)
DS: (32,687) (1192,1627)
Medley Phase (Final) Band Plan
US: (0,95) (696,1183)
DS: (32,687) (1192,1627)

17a profile:-
Discovery Phase (Initial) Band Plan
US: (0,95) (868,1207) (1972,2783)
DS: (32,859) (1216,1963) (2792,3939)
Medley Phase (Final) Band Plan
US: (0,95) (868,1207)
DS: (32,859) (1216,1963)

My bit-loading cuts off at around tone 1750, usually lower, so the increase in DS tones from 1627 (8c) to 1963 (17a) is pretty much wasted for my connection.


Which full modem stats pic do you mean?
I have some graphs from my 8c connection & thousands from my 17a connection, if that's what you meant.
Standard User qasdfdsaq
(regular) Mon 07-May-12 16:21:06
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
In reply to a post by Bald_Eagle1:
Which full modem stats pic do you mean?
I have some graphs from my 8c connection & thousands from my 17a connection, if that's what you meant.

One of the "combo" ones like the one I posted. I'd like to see noise and attenuation across the spectrum.
Standard User Bald_Eagle1
(committed) Mon 07-May-12 16:34:04
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
Here's one from this morning, just after the connection resynced "on the fly"

Current_Stats
Standard User qasdfdsaq
(regular) Mon 07-May-12 16:35:16
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
How long is your line? Or rather what's your distance to cabinet if you know? And what does BT estimate your speed should be?
Standard User Bald_Eagle1
(committed) Mon 07-May-12 16:46:19
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
Engineers have reported it as various lengths, between 820m & 1100m.

I physically measured what I believe to be the route at just less than 1000m (using a trundle wheel).
It could be possibly between 900m & 950m depending on exactly where/how it crosses the main road & up the road to the cabinet itself.

When FTTC was installed, my estimate was 14.6Mb & I achieved 35Mb sync speed.

Shortly after 17a was introduced my estimate went up to 24Mb.

Currently my estimate is 30Mb.

FWIW, here's a graph of my IP Profiles (not sync speeds):-

IP Profiles

Some of the data from the first month is a bit vague.
My connection was that good back then that I didn't need to monitor it every day.

All the really low profiles are from the intermittent issues that have needed engineer visits.
Faults were found & supposedly fixed at every visit!!!

Edited by Bald_Eagle1 (Mon 07-May-12 16:53:19)

Standard User RobertoS
(sensei) Mon 07-May-12 17:35:05
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
I also used a shorter modem lead and wired it straight into the socket (the filtered IDCs behind the bottom plate) which also cut off about 0.3-0.5dB.
?????
Pardon?

Do you mean the un-filtered?

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Standard User qasdfdsaq
(regular) Mon 07-May-12 17:36:28
Print Post

Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
In reply to a post by qasdfdsaq:
I also used a shorter modem lead and wired it straight into the socket (the filtered IDCs behind the bottom plate) which also cut off about 0.3-0.5dB.
?????
Pardon?

Do you mean the un-filtered?

Nope, I meant the filtered ones.
Standard User RobertoS
(sensei) Mon 07-May-12 17:47:53
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
You have me thinking I've thrown a complete wobbly!

There should be no VDSL2 signal on filtered terminals. The filter is supposed to removed anything outside audible frequencies from the output, as otherwise you wouldn't be able to use the phone because of the racket. xDSL connections are unfiltered.

I don't think I've gone mad. So either I have, or you are not correct in what you say you have done, or you need to see what happens if you connect the modem with a standard ADSL cable into the DSL socket on the front of the faceplate.

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

Edited by RobertoS (Mon 07-May-12 17:48:16)

Standard User Croftie
(member) Mon 07-May-12 17:48:32
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
btw, imgbox.com is free and doesn't have a resolution cap wink
Standard User BatBoy
(legend) Mon 07-May-12 17:48:45
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
In reply to a post by RobertoS:
In reply to a post by qasdfdsaq:
I also used a shorter modem lead and wired it straight into the socket (the filtered IDCs behind the bottom plate) which also cut off about 0.3-0.5dB.
?????
Pardon?

Do you mean the un-filtered?

Nope, I meant the filtered ones.
Only the phone is filtered. The broadband is unfiltered.


_____________________________________________________________________________________________ this is not usenet __________________
Standard User qasdfdsaq
(regular) Mon 07-May-12 17:53:46
Print Post

Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
You have me thinking I've thrown a complete wobbly!

There should be no VDSL2 signal on filtered terminals. The filter is supposed to removed anything outside audible frequencies from the output, as otherwise you wouldn't be able to use the phone because of the racket. xDSL connections are unfiltered.

I don't think I've gone mad. So either I have, or you are not correct in what you say you have done, or you need to see what happens if you connect the modem with a standard ADSL cable into the DSL socket on the front of the faceplate.

There are two sets of connectors - one for xDSL, one filtered telephone (for phone extensions), then there's the "master" connector on the NTE5 too, but that's not meant to be customer accessible.

I've (obviously) connected it to the one meant for xDSL, though whether that's xDSL filtered or completely unfiltered I'm not sure - I assumed the xDSL and phone sockets were two oppositely filtered (or two sides of the same filter) points - but if you say the xDSL is completely unfiltered, then sorry - I did mean unfiltered, I just didn't know it. I always just thought the DSL side had voice filtered out and vice versa.
Standard User RobertoS
(sensei) Mon 07-May-12 18:10:18
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
Phew! smile

xDSL lines are unfiltered.

However, what about the phone(s) now. From memory, as I have to dog-walk, if picking up the phone causes a problem have you tried an extra normal dangly filter on the phone socket? This could be a red herring, but as I said, I haven't time to check back through the thread.

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Standard User Bald_Eagle1
(committed) Mon 07-May-12 18:16:02
Print Post

Re: New speeds upgrade question


[re: Croftie] [link to this post]
 
In reply to a post by Croftie:
btw, imgbox.com is free and doesn't have a resolution cap wink


Ah that's better (the resolution, not the stats) smile

72 Day Stats
Standard User qasdfdsaq
(regular) Mon 07-May-12 18:40:11
Print Post

Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
I haven't tried an extra dangly filter, no. I'm not that fussed about the phone, as we only ever use it to avoid the monthly "you did not use the phone" penalty charge. Previously, my attainable rate would drop from 87 to 82, now I've improved attainable by about 5mbps, I'd expect a drop from 94 to 89, still plenty above the 80mb cap anyway.

If it does ever drop to the point it actually causes a problem, I'll take another look, for now I'm just leaving it disconnected till DLM (or an engineer) declares my line fit again.
Standard User Croftie
(member) Mon 07-May-12 20:23:03
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
Hehe, I've not forgot about you smile
Standard User RobertoS
(sensei) Mon 07-May-12 21:14:50
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
It was Bald_Eagle's 4dB drop sometimes when using the phone that had come into my head.

If that had been on your connection I would have been wondering if the filter in the faceplate had given up. Hence the suggestion of adding a dangly smile.

In his case, it looks more like a D-side problem.

My broadband basic info/help site - www.robertos.me.uk
My domains,website and mail hosting - Tsohost. Internet connection - Plusnet Value Fibre.

"Where talent is a dwarf, self-esteem is a giant." - Jean-Antoine Petit-Senn.
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Standard User qasdfdsaq
(regular) Mon 07-May-12 21:32:14
Print Post

Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
Ah, right. Yes, 4dB is quite a drop and my connection loses about 5 megabits per dB!

Bald_eagle1's line is quite odd. At that length, I'd expect about double the speed he's seeing. Some sources say even up to 80 is possible at that length, but closer to ~50 under "average" crosstalk conditions.
Standard User Bald_Eagle1
(committed) Mon 07-May-12 22:50:48
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Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
It doesn't help that we don't have a simple to evaluate attenuation value for VDSL2 connections (certainly not via the HG612 modem), although an engineer's JDSU does combine attenuation from the 3 DS & US bands into single DS & US values.

From what I have seen of other connections, my attenuation values right across the board would have to be quite a bit lower to achieve higher speeds.

What I unforunately do not have is any attenuation values from when FTTC was installed.

I am convinced that whatever caused my connection to go awol for 4 days last July has never been fully rectified, leaving me with higher attenuation values & therefore susceptibility to "noise interference" than I had at first.
I just can't prove it frown

Apparently 13.8dB per km is typical attenuation for 0.5mm twisted pair copper cables.
23dB is the lowest DS attenuation value reported from an engineer's JDSU.
Once over, 30.2dB was reported, again from a JDSU.

Edited by Bald_Eagle1 (Mon 07-May-12 22:55:40)

Standard User Bald_Eagle1
(committed) Tue 08-May-12 08:43:21
Print Post

Re: New speeds upgrade question


[re: RobertoS] [link to this post]
 
In reply to a post by RobertoS:
It was Bald_Eagle's 4dB drop sometimes when using the phone that had come into my head.

If that had been on your connection I would have been wondering if the filter in the faceplate had given up. Hence the suggestion of adding a dangly smile.

In his case, it looks more like a D-side problem.


When this happens, I do try a dangly filter in the usual phone socket (no improvement) & also in the user accessible test socket (again, no improvement).

I think engineers have also suspected the master socket filtering as the cause as one replaced the whole thing & another replaced the filter pcb.

It just has to be a D-Side issue (unless it's the DSLAM itself or the patch cable connections in the fibre cabinet).

Modems have been replaced.
My drop wire has been replaced, removing the engineer installed data extension in the process.
I have run my connection with everything except VDSL2 disconnected for 2 week periods.
Twisted D-Side pairs have been swapped.
Exchange side Lift & Shift has been done.
Double-jumpered cabinet connection has been removed.
Engineers have run TDR tests & other "basic" tests - All result in LTOK.

There isn't much left to test & getting an engineer on site just when the issue is evident seems impossible.

It usually lasts for 3 or 4 days or so, completely ruining my connection speeds, but it takes more or less a week to organise an engineer visit, so the issue has gone again by the time they arrive.

More recently it appears that dry & warm weather starts it off (which seems to be the complete opposite to the usual water in the cable/joints issues).
Simply dialling in seems to effect a temporary cure (after initially causing a disconnection & banding my connection at a ridiculously low sync speed)frown
Standard User qasdfdsaq
(member) Tue 08-May-12 17:30:48
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
I've just found your epic thread on the other forum you mentioned - sounds like you're getting pretty decent support from Plusnet on the whole, but unfortunate the problem itself hasn't been fixed...

Anyhow. Your attenuation would have to be lower to get higher speeds, yes, but your attenuation for an ~850m long line is unusually high.

It's not as easy to quote a single attenuation value for the whole spectrum on VDSL2 as it is on ADSL - there's huge variations across the different bands, then there's the fact there's multiple bands to begin with, which can vary. There's no standard for combining the readouts for the different bands either, so the per-band and per-tone readings off the HG612 are the best we can get. To be honest I think they provide a much better reading than any individual or per-band attenuation figure anyway.

I see you've posted elsewhere "good" and "bad" line stats examples, I presume the bad one is yours - not sure where the "good" one is from, but I'd expect an 850m line to be around halfway between those two, with full usage of the D2 band and maybe a touch of D3.

Given you've basically replaced everything except the cab and underground cable, you're right to suspect one of the two. I recall you mentioned an engineer once tested your line at the cab, and got a full 80mb sync. Do you happen to know what the max attainable rate was showing in that test? 80 doesn't really say much at the cab, it should really be around over 150mbps to be meaningful.

Incidentally I've decided to report a fault on my line now, as it's not just the DLM speed capping getting in my way. I've noticed picking up the phone causes a spike of FEC errors on my modem stats and packet loss on my TBB BQM as well as a short-term drop in SNRM from ~7 down to ~2, before it gradually recovers. That's even with the line synced at ~47 out of 90mbps and a dangly filter.

Edited by qasdfdsaq (Tue 08-May-12 17:33:25)

Standard User Bald_Eagle1
(committed) Tue 08-May-12 18:16:35
Print Post

Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
I've just found your epic thread on the other forum you mentioned - sounds like you're getting pretty decent support from Plusnet on the whole, but unfortunate the problem itself hasn't been fixed...

Anyhow. Your attenuation would have to be lower to get higher speeds, yes, but your attenuation for an ~850m long line is unusually high.

The main problem seems to be that the faults(s) are intermittent, apart from what does appear to be quite consistently high attenuation over a relatively short distance.


It's not as easy to quote a single attenuation value for the whole spectrum on VDSL2 as it is on ADSL - there's huge variations across the different bands, then there's the fact there's multiple bands to begin with, which can vary. There's no standard for combining the readouts for the different bands either, so the per-band and per-tone readings off the HG612 are the best we can get. To be honest I think they provide a much better reading than any individual or per-band attenuation figure anyway.

Agreed.
A few of us have tied to suss out a formula for combining the split attenuation values into a single value as that is what most engineers are familiar with.
I believe a JDSU can actually report split attenuation values, just like the HG612 modem, so I was most disappointed when the latest engineer turned up with an Exfo instead of the usual JDSU.
He was a most helpful engineer, who did look for the split figures to compare against my modem stats & relate back to his single values, but it appears the Exfo doesn't report that.


I see you've posted elsewhere "good" and "bad" line stats examples, I presume the bad one is yours - not sure where the "good" one is from, but I'd expect an 850m line to be around halfway between those two, with full usage of the D2 band and maybe a touch of D3.

I'd now be quite happy to achieve a 40Mb & stable connection as I never really expected to exceed that anyway.
I only wish I had recorded the connection stats at installation time for comparison against my current stats.
At that time I had no idea that I would not be able to see my own connection stats.


Given you've basically replaced everything except the cab and underground cable, you're right to suspect one of the two. I recall you mentioned an engineer once tested your line at the cab, and got a full 80mb sync. Do you happen to know what the max attainable rate was showing in that test? 80 doesn't really say much at the cab, it should really be around over 150mbps to be meaningful.

The engineer said his Exfo (not a JDSU that time) had synced at 80Mb at the cab, so I don't know what the Max Rate was at the cab.

By the time my D-Side had attenuated it, these were the modem stats:-

Text
1
23
45
67
89
1011
1213
1415
1617
1819
2021
22
# xdslcmd info --pbParams 
xdslcmd: ADSL driver and PHY statusStatus: Showtime
Retrain Reason: 2Max:    Upstream rate = 6376 Kbps, Downstream rate = 35864 Kbps
Path:   0, Upstream rate = 6372 Kbps, Downstream rate = 35322 Kbps 
Discovery Phase (Initial) Band PlanUS: (0,95) (868,1207) (1972,2783) 
DS: (32,859) (1216,1963) (2792,3939) Medley Phase (Final) Band Plan
US: (0,95) (868,1207) DS: (32,859) (1216,1963) 
       VDSL Port Details       Upstream        DownstreamAttainable Net Data Rate:       6376 kbps         35864 kbps
Actual Aggregate Tx Power:        6.2 dBm          12.2 dBm============================================================================
  VDSL Band Status        U0      U1      U2      U3      D1      D2      D3  Line Attenuation(dB):  8.2     53.0    64.1     N/A    21.6    63.2    0.1    
Signal Attenuation(dB):  14.4    52.5     N/A     N/A    21.6    63.2     N/A           SNR Margin(dB):  6.0     6.1      N/A     N/A    6.3     6.4      N/A   
         TX Power(dBm): -4.3     5.8      N/A     N/A    10.9    6.4      N/A



Incidentally I've decided to report a fault on my line now, as it's not just the DLM speed capping getting in my way. I've noticed picking up the phone causes a spike of FEC errors on my modem stats and packet loss on my TBB BQM as well as a short-term drop in SNRM from ~7 down to ~2, before it gradually recovers. That's even with the line synced at ~47 out of 90mbps and a dangly filter.

Sounds very similar to my current intermittent issue(s).
Please keep us posted as to how you get on with matters.
Standard User BatBoy
(legend) Tue 08-May-12 20:00:24
Print Post

Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
In reply to a post by Bald_Eagle1:
A few of us have tied to suss out a formula for combining the split attenuation values into a single value as that is what most engineers are familiar with.
The way I would do it is to convert them to milliwatts, add them up and take the average or the mean. Then convert the result back.


_____________________________________________________________________________________________ this is not usenet __________________
Standard User qasdfdsaq
(member) Wed 09-May-12 15:16:23
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Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
In reply to a post by Bald_Eagle1:
Sounds very similar to my current intermittent issue(s).
Please keep us posted as to how you get on with matters.

BT's online fault tracker seems to claim they fixed the fault in about an hour, despite them having done nothing of note or contacted me. No phone call, no engineer, not even a resync of my line. Until...

Right on time at 6am this morning, DLM changed my cap and triggered another resync - now I'm at 53998 down, 20000 up. Interleaving appears to be even higher, which is a pain since my main uses for my connection are gaming and remote desktop/ssh.

Picking up the phone still reduces my DL attainable rate by 5mbps, but increases upstream SNR and doesn't cause any packet loss or errors now. Perhaps DLM increased impulse noise protection and interleaving for that, which simply stinks.

All in all... DLM = total PITA and BT support = meh.
Standard User Bald_Eagle1
(committed) Wed 09-May-12 16:49:57
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Re: New speeds upgrade question


[re: qasdfdsaq] [link to this post]
 
In reply to a post by qasdfdsaq:
Picking up the phone still reduces my DL attainable rate by 5mbps, but increases upstream SNR and doesn't cause any packet loss or errors now. Perhaps DLM increased impulse noise protection and interleaving for that, which simply stinks.

That really is peculiar.
What happens to upstream attainable rates when upstream SNR(M) increases & what happens to downstream SNR(M) when downstream attainable rate reduces by 5Mb?



All in all... DLM = total PITA and BT support = meh.

I Can't comment on BT support as I'm with Plusnet, but I agree 100% that DLM = total PITA.

Perhaps you need a connection like mine:-

Stable Connection???

Despite simply using the phone sometimes causing disconnections, this is apparently the current status of my connection:-

"With your line we can see the sync rate and stability is within limits and so it is unlikely that further engineers will be able to find any problems."
Standard User qasdfdsaq
(member) Wed 09-May-12 17:53:41
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Re: New speeds upgrade question


[re: Bald_Eagle1] [link to this post]
 
In reply to a post by Bald_Eagle1:
In reply to a post by qasdfdsaq:
Picking up the phone still reduces my DL attainable rate by 5mbps, but increases upstream SNR and doesn't cause any packet loss or errors now. Perhaps DLM increased impulse noise protection and interleaving for that, which simply stinks.

That really is peculiar.
What happens to upstream attainable rates when upstream SNR(M) increases

No real change, it goes from 30400 down to maybe 29800. Certainly nowhere near the drop down to 15000 I was getting yesterday.

& what happens to downstream SNR(M) when downstream attainable rate reduces by 5Mb?

About 1dB reduction.



I Can't comment on BT support as I'm with Plusnet, but I agree 100% that DLM = total PITA.

Perhaps you need a connection like mine:-

Stable Connection???

Honestly I'd rather have a slow and unstable connection with interleaving off so my pings stay low. That's the main reason I switched from VM - despite them having slightly lower minimum latency, the horrendous jitter 24/7 meant the average ended up 50% higher, and the pathetic 1.5mbps upload didn't help either.

Despite simply using the phone sometimes causing disconnections, this is apparently the current status of my connection:-

"With your line we can see the sync rate and stability is within limits and so it is unlikely that further engineers will be able to find any problems."

Perhaps you should try using your phone repeatedly so disconnections get to the point where it is no longer within limits? tongue

Edited by qasdfdsaq (Wed 09-May-12 18:12:14)

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