Kitz Forum

Broadband Related => FTTC and FTTH Issues => Topic started by: broadstairs on January 17, 2017, 10:40:20 AM

Title: Is my line banded or capped in some way?
Post by: broadstairs on January 17, 2017, 10:40:20 AM
I had been running for over 128 days on my line until yesterday evening when the router decided to stop allowing telnet. My SNRM had dropped considerably over that time and my attainable was well below my actual. On the reboot and therefore resync I expected my SNRM to return to around 6db and the actual to drop to somewhere around the 55000kbps which was where the attainable was.

Now as can be seen on MDWS my attainable is 64036kbps but my actual is 59995kbps with an SNRM of 7.3db. With that attainable I expected the actual to be closer to that value with a 6db SNRM.

So am I banded or capped in some way, if so can anyone suggest how or why? I am on the Fibre large with TalkTalk. The sync value has been set at that value since earlier in 2016 following some problems with my line which were never fixed but have not recurred. What bothers me is that in the future if/when G.INP returns or the 3db sync is introduced I will not gain anything.

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: Chrysalis on January 17, 2017, 10:51:11 AM
a load of 9s after the 5 and high snrm suggests banding yes.
Title: Re: Is my line banded or capped in some way?
Post by: licquorice on January 17, 2017, 02:17:19 PM
Yep, if it stays the same when re-resyncing , almost definitely banded at 60M except that https://community.plus.net/t5/Library/FTTC-DLM-What-it-is-How-it-works/ba-p/1322799 doesn't show a 60M band limit.
Title: Re: Is my line banded or capped in some way?
Post by: broadstairs on January 17, 2017, 03:00:05 PM
I have raised a thread on the TT forum asking why my line syncs at such an exact speed with a higher than expected SNRM?

I expect I will get all the usual claptrap from TT but I will try to get an answer.

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: Sheepie on January 17, 2017, 03:44:20 PM
I was banded at 60M exactly and was like that for over a month before I had to get DLM reset.
Title: Re: Is my line banded or capped in some way?
Post by: peterj on January 17, 2017, 11:14:59 PM
I have been banded at 35 since last summer and have had low ES for some time since. I am not sure it is ever going to be lifted without a reset by an engineer. I have ignored as not worth the effort for 5M.
Title: Re: Is my line banded or capped in some way?
Post by: broadstairs on January 18, 2017, 10:52:58 AM
As expected I got the usual response from TT  >:( The line is in sync with the predicted speed range and therefore nothing we can do. I've told them this is unacceptable and I want to escalate this but don't hold out much hope  ;)

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: Sheepie on January 18, 2017, 11:12:20 AM
It seems odd that you've been banded before any other form of interleave/delay has been applied. If your line was having errors I would have thought the first thing DLM would do is interleave?
Title: Re: Is my line banded or capped in some way?
Post by: j0hn on January 18, 2017, 11:31:49 AM
It appears your line was banded back in July. You had a large ES spike of about 3500 in 1 day. Interleaving was applied the next day and the sync has been 59995 (or below) since then.
Title: Re: Is my line banded or capped in some way?
Post by: broadstairs on January 18, 2017, 11:52:45 AM
@Sheepie the banding was done last summer when I was having big problems with the line and had 3 BTOR visits over a two month period, none of which I was charged for.

The 59995 was applied to my line following issues which ended with 3 visits from BTOR guys and at least two resets. The sync at the time things seemed to settle down was 59995which at the time was not unreasonable given the SNRM. The last of the issues were around the start of September, after that the line stayed up for 128+ days until I had the telnet issue.

I did believe my line was banded somehow back then but thought if that were the case the longer I left it up the more chance the banding would be removed by BT/DLM which obviously did not happen.

Now TT are basically washing their hands of it all because my actual sync is within the predicted range.

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: Sheepie on January 18, 2017, 01:44:10 PM
The engineer that did a DLM reset on my line last week did say that TalkTalk really do not like arranging engineer visits, they will do ANYTHING to avoid it in fact. It looks like all you need is a DLM reset to remove stuck banding, but an engineer visit is required for that.
In my case, I had a stuck 60M profile for just a month but my ISP (Zen) agreed that it looked like it was stuck and arranged for an engineer visit, and even if they did not find any fault I would not be charged. As part of DLM reset he said he had get all line tests passed before that could be done.
It was interesting that after he did DLM reset the line was on interleave, but he just called up some OR call centre and got them to change the line to remove all interleave - so they do have remote access to at least the DSLAM.

Going back to TalkTalk - I have a 2nd ADSL+ LLU line with them, and after a fault (sync was fine but ppp failing) it took me 4 weeks to convince them to send out an engineer - I had no internet access at all during this time and the only compensation they would give me was a months worth or subscription refunded (the month where I had no access!). Imagine if this had been my only line - I work from home!
TalkTalk are cheap for a reason.........

So unless you get a fault I doubt TalkTalk will do anything.
Title: Re: Is my line banded or capped in some way?
Post by: peterj on January 18, 2017, 01:46:09 PM
Is it confirmed that once banding has been imposed it isn't ever lifted without an engineer resetting the line to totally open status or is this info not in the public domain? It sure seems that way.
Title: Re: Is my line banded or capped in some way?
Post by: Chrysalis on January 18, 2017, 02:36:14 PM
I do remember reading a document somewhere where CPs can actually request banding.

So e.g. lets say a customer has a problematic line and has had multiple engineer visits, the CP might want to band the line to reduce problem reports.  I dont know if the banding product was designed for that purpose, I just remember reading a document stating it can be requested.
Title: Re: Is my line banded or capped in some way?
Post by: broadstairs on January 18, 2017, 05:14:57 PM
As expected TT have refused point blank saying that DLM only sets the criteria and there is nothing which can be done. They say if I'm still not satisfied I can start an official complaint which is what I intend to do.

I am just wondering if anyone here knows how such a banding is done normally and is it always an arbitrary maximum which is set or a value which is always used no matter what the SNRM is? I suspect the former or there would be issues. Next question is basically can this only be done by intervention of BTOR staff or can DLM do it without manual intervention? Again I suspect the former but would like to know.

I am planning to argue my case on the basis that an arbitrary upper limit below the max allowed by my contract in unreasonable especially as if/when G.INP is re-enabled on ECI cabinets my line will be unable to see any benefit (my sync while G.INP was active was around 71000kbps and stable) and the same applies if the 3db SNRM is activated - no benefit to me.

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: peterj on January 18, 2017, 08:34:57 PM
My banding happened after a few high error days and one particullarly bad day with 1600 ES. I hadn't reported a fault so would be quite suprised if it was a BTOR intervention. It continued to be bad for ES a week after banding and then returned to normal on its own. It just seems to me that DLM applies banding, but once it is applied it is never removed.
Title: Re: Is my line banded or capped in some way?
Post by: broadstairs on March 01, 2017, 09:31:38 AM
Well I opened my complaint with TT and it got no response for 3 weeks, so I complained to the CEO. After another delay and some emails back and forth I have been informed by someone in the CEO's office that they will have to arrange a BTOR visit to remove the banding. I am now waiting to hear what will happen next and whether or not they will expect me to accept any charge (I think you can guess my answer to that one if it comes  :thumbdown: ).

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: broadstairs on March 20, 2017, 04:07:56 PM
Well after much more discussions I'm sure no one here will be surprised that the bottom line here is nothing will be done. As my line cannot attain a stable green ILQ they are unable or unwilling to do anything.

I have been doing a little testing over the past few days to see if my line could achieve and perhaps sustain a green ILQ but having reduced sync speed to 55000kbps and then 50000kbps I have proved that the line will not achieve a stable green ILQ at those speeds and frankly I suspect it will not matter how low I go the line behaviour seems to make it unlikely to get to a stable green ILQ at all. What this I believe indicates is that whatever was severely wrong with my line last June through September albeit intermittently has never been properly or fully diagnosed or resolved, whatever happened to resolve it has simply reduced in severity to an extent that I can achieve an amber ILQ status which is fairly stable and I am certain that nothing was actually done to the line to fix anything. I suspect that whatever the fault is it is likely to happen again in the future (maybe we need an HGV to hit the cab  :-X or some other local disaster). If said fault does re-appear then I hope it goes solid and they cannot then slope shoulders on it as happened before.

As to the actual error rates I see there is no pattern to them and they occur at random times, last night for example it was most of the evening and night when ES were high. I see sudden spikes of CRCs at random times of the day and night otherwise it bumbles along at maybe one or two every couple of minutes.

I'd be interested to know how the ES count correlates to the other errors, for example does just 1 CRC in a second cause that second to be counted as an error second, and what other errors will cause the ES count to be incremented?

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: ejs on March 20, 2017, 04:41:46 PM
Amber ILQ is defined is OK, with green defined as better than expected.

Yes 1 or more CRC errors in a second make it an errored second. The G.997.1 definition of ES includes LOS, SEF and LPR defects, but I don't think anyone will need to worry about the counts of those.

The LOS, SEF or LPR would also make it a SES, as would 18 or more CRC errors in the second.
Title: Re: Is my line banded or capped in some way?
Post by: broadstairs on March 20, 2017, 05:35:13 PM
Amber ILQ is defined is OK, with green defined as better than expected.

The issue when banded is that you need to be green to have the banding removed by DLM. It may be classed as OK butwhen they band it to simply bypass a fault I believe that is unacceptable, they should fix the fault not limit the speed.

Stuart
Title: Re: Is my line banded or capped in some way?
Post by: ejs on March 20, 2017, 05:52:08 PM
I thought people were finding that the automatically applied banding never gets removed no matter how many weeks of green ILQ. We certainly don't get many people reporting that they've been banded for a while, then it lifted.
Title: Re: Is my line banded or capped in some way?
Post by: j0hn on March 20, 2017, 09:47:30 PM
Talktalk are just filling you with nonsense. Banding should remove before the line returns to fastpath.

DLM requires lines to be ILQ green to remove certain parameters set on the line. That's sensible with some form of error protection on the line. There's really not that many lines that can stay ILQ green while completely open on fastpath.

At the moment it's not affecting your service. I would ignore it as Talktalk aren't going to agree to an engineer without threatening you with the callout charge. When(if) they fix G.INP on ECI cabinets and they introduce the lower dB SNRM then raise the issue with Talktalk again.
Title: Re: Is my line banded or capped in some way?
Post by: NewtronStar on March 20, 2017, 11:26:04 PM
Well he could migrate to another ISP that will remove any banding on the circuit, as long as term with current provider is halfway then no major fee's for leaving early, but my bet he is getting FTTC must cheaper with LLU than I and others and will remain with TT ISP  ;)