Line banding frustration.

[#1]

So once again I am fed up with all things ADSL/VDSL/BT/Openreach/Plusnet.

Why do you all conspire against me so?

I have a reasonable ADSL connection, that works almost all the time, with perhaps a few days a year with instability.

In the old days I would connect and sync as fast as possible, a crappy IP profile would then be used to make it as slow as possible.

But then ADSL2 came and all was wonderful (even while I was on TalkTalk, as an old Nildram account). It would connect as fast as it could, and I would get most of the speed, all I had to watch for was sneaky TalkTalk turning on interleaving and the odd SNR margin target change.

However the last couple of years with plusnet, have just been me calling support for several days in a row after an issue and getting worse and worse limits imposed on the now functional line again.

Yesterday I was at 2272 after a fault, I call support and wait, nothing happens. Today finally at 10am the change went through, I am now connected at 1152. Thanks a lot...

So this evening I call, and am first caught off guard as someone answered (usually it's closer to an hour on hold). So after we eventually get me authenticated (I realise now I forgot an extra digit in the passphrase, but additional information was sufficient). I move on the main issue..

I request a reset again, with interleaving disabled and for the line banding to be removed from my line. I am told I can have 4Mb, but no more. Excuse me? Can I not have it unbanded? I am told it's based on the BT estimate of up to 3.5Mb.

Well I'm sorry, BT are the last people you should ask about estimates for this line! The ADSL is too low and the VDSL was only half the estimate! (two weeks of 5Mb "Fibre"!).

So after some increasingly grumpy back and forth I give up, because the "estimate" is the ultimate power in such issues it seems.

I have crappy internet, I want it to go as fast as it can! I *know* it will disconnect, I reboot the modem at night, I buy broadcom Modems to keep the sync as long as possible, I know my line stats inside out....

Please do not arbitrarily make my line even slower than it need be! Current estimate is around 4900 which I know I wouldn't get, but I would get slightly more than the 4544 I was capped to previously on a good week.

Is anyone able to tell me why it *must* be banded? It never used to be.

In despair..

David.

[#2]

Hi David,

Ultimately you are limited by physics - the quality of you line and its length.  Let's look at some facts and see what gives here...

Please post your router stats; for PN TG582n and 2704n routers use the buttons below. Also run a BT Wholesale speed test (ideally using an Ethernet wired PC with the WiFi turned off) then run the further diagnostics and post the results here. DO NOT REBOOT the router! Also find your CURRENT SPEED (PlusNet line profile) from the PlusNet user portal - you will need to log in.

• TG582n Stats
• 2704n Stats
• BTw Speedtest
• PN Profile

[#3]

I know this, I know my line is slow due to length and attenuation.

I want to know why it has to be made even slower still by an arbitrary hard sync limit based on an inaccurate BT estimate.

[#4]

As I said, let's have some stats (facts) to look at and then we can start passing objective opinion.  Lines only get banded due to stability issues.

Please post your router stats; for PN TG582n and 2704n routers use the buttons below. Also run a BT Wholesale speed test (ideally using an Ethernet wired PC with the WiFi turned off) then run the further diagnostics and post the results here. DO NOT REBOOT the router! Also find your CURRENT SPEED (PlusNet line profile) from the PlusNet user portal - you will need to log in.

• TG582n Stats
• 2704n Stats
• BTw Speedtest
• PN Profile

[#5 · Accepted solution]

I've passed feedback on regarding the advisor you spoke to. Although they changed the speed profile to 4Mbps, the line was banded at 1Mbps, so this made no difference.

I've now put a request through to un-band the line and make sure there is no interleaving as requested.

I've also set the profile to 4700 as it should be, in line with the new sync speed of 5363, however DLM may alter this if the connection starts dropping again.

I hope this helps.

[#6]

Harry,

Has the reason for banding the line been identified and rectified? 

Contrary to what the OP suggests, lines are not banded for arbitrary reasons such as estimated performance capability.  That's why I asked the user for the stats - attenuation, synch speed, SNRM and error counts disclose a lot of useful information about what is happening.

I hope that the cause of the banding has indeed been rectified, otherwise the user will be back here in a few days time, only to get the same request for detailed stats. 

[#7]

Well testing the line resulted with:

Problem Explanation: [ OD01 ] The Line associated with the provided Service id is currently in Fault. Resolution / Recommendation: Refer End User to telephony provider to confirm PSTN fault open.

However as Ratbert had said:

Yesterday I was at 2272 after a fault

I have taken this to mean that his phone provider has advised the fault has been resolved.

Following the change I put through to remove banding/interleaving a status check shows the following:

Upstream DSL Link Information Downstream DSL Link Information Loop Loss: 29.3 49.0 SNR Margin: 6.5 5.6 Errored Seconds: 6 0 HEC Errors: 2   Cell Count: 1250058 872009 Speed: 867 5363

Maximum Stable Rate (KBPS): 4000 Fault Threshold Rate (KBPS): 3200 Mean Time Between Retrains (Seconds): 12105 Mean Time Between Errors Upstream (Seconds): 100 Indicative Line Quality: R Mean Time Between Errors Downstream (Seconds): 81

ILQ/MTBE doesn't look great, but we'll see what happens with the requested change

[#8]

There was a fault, a 10dB increase in attenuation and no dial tone, this was resolved by BT without a visit as it was not at the property.

This was fixed and the stats returned to normal. Occasionally (perhaps once or twice a year) there is some interference and line speeds drop for a few hours but usually return to normal, but then require multiple calls to get dlm back to normal, last time a 4554 limit was left in place and I gave up trying to get it reset as it had already spend three evenings on hold.

[#9]

Thanks for the reset and removal of the banding, I will reboot the modem tonight when the snr drops and it should be stable again.

[#10]

There should be no need to reboot the modem/router.  The work done by PlusNET will have caused a resynch.  Unessential rebooting could cause the DLM to think that there's still a stability issue and cause it to reimpose banding.  The line already has a red ILQ so leave well alone and avoid reboots.

[#11]

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@Townman wrote:

The work done by PlusNET will have caused a resynch.

You would think so wouldn't you, but the intrusive test I ran doesn't seem to have caused the session to drop  so a reboot may be worthwhile.

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[#12]

@HarryB,

Thats right odd.  I would have expected that a successful order to lift the banding would have forced a resynch. Just shows what thought did! 

[#13]

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@HarryB wrote:

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@Townman wrote:

The work done by PlusNET will have caused a resynch.

You would think so wouldn't you, but the intrusive test I ran doesn't seem to have caused the session to drop  so a reboot may be worthwhile.

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The session is initiated from a pfsense box, so the PPPoE session is a bit more "sticky" and often survives re-syncs.

[#14]

That's very interesting! Gives another scenario where use of the PPP session VR plot to identify synch disconnections might be flawed.  Would be good to see the modem stats before you bounce it please.

@HarryB How would this be handled by the PN systems?  Do they rip down the PPP session if there's a break in synch or do they only die after some separate timeout?

Do BTw systems indicate a loss of synch when expected?

[#15]

Indicative Line Quality: R

Out of interest, which parameter(s) put it into Red?   Third party information suggests that it would need MTBE of 5 or less, and/or MTBR of 8640 or less.