In reply to a post by mixt:

lol, ok, thanks for the corrections.
...
one of these annoying cases where BT just wont see anything wrong with it

For a few months now it has been increasingly obvious that if you have a broadband connection at any level then Openreach are not interested in a variety of problems.

Even previous better performance is irrelevant. Worse still, ISPs seem to be encouraged to use the "SNR reset" facility willy-nilly to correct speed problems, which can be a disaster as it doesn't simply do that - it restarts a 10-day training period. If there is a fault causing low speed, rather than an excessively high margin being the reason, this results in the MSR and FTR being lowered, whereupon the poor performance automatically comes within range for that line so OR won't even accept a speed complaint.

Yeah, I'm with you, and I mostly agree.

My brother got BE on his business (office) line up north (Newcastle) some years ago now. The checker reported he should get 12 odd Mb sync.

I setup all his kit (routers etc) so they log stats to an online server, one of these stats being the SNR. He plugged the router in and it synced at.... 3 Mb, for about... 2 weeks. Then for around 5 days, the sync went all the way to 12 Mb. I was amazed.

After this, it dropped again back to 3 Mb. I tried to log this as a fault with BE, but given that I'm not actually the line or account owner, it was kind of difficult to go anywhere with them. The monkey on the phone reeled off the usual 'we can't see any fault on the line, this is to be expected'. The fact that it did achieve a 12 Mb sync for 5 days a few days previous went right over his little head. If this had been AA, they would have logged this (they log everything!) and they would have had all the ammo required to put the gloves on and pay BT a visit.

But, it wasn't, so that hasn't happened. His line has been this way for the past 2 years - still 3Mb, still chugging along. It doesn't bother him as they are not using the connection in any intensive/fast way. But if it was me, I would be all over that as one major fault that someone (BT) needs to fix.

Right now he has a 40.0 db line attention, synced at 2,752Kbps with an 8db SNR - *that* *is* *pretty* *disgusting* - but it ain't my line, and it works... so, let's leave it alone!

Edited by deleted (Sat 02-Jul-11 23:18:46)

Just doing another test & replaced the micro filter, plugged all ethernet devices out - just the modem. Have done this 4-5 times before with no luck.

Ok, as I said before, organise moving yourself to AA.

As soon as you are with them, they will start to monitor your line and graph latency/packet loss continuously (they do this at the PPP/LCP layer, not at the IP layer). This allows both them and yourself to see -precisely- how the line is behaving over time, and gives them something to work with when escalating to BT.

They will not give in until you are happy with the result. As I said, I think the downer here is the fact you are -wanting- to run fast path, on what appears to be a poor line. So either the line fault (if there is one) is going to get fixed, or they are going to help work the problem (increase your SNR, do what ever is required) to deliver a working broadband connection that works in the way you want it to.

Let us know how you get on. Btw, if it helps you at all, I phoned them once a few months back cause I had a line fault. They took a while to answer, but I never found myself in a queuing system, and I told the guy all the usual tests I had done with my line and within 30 seconds he basically organised a BT engineer call out (which I subsequently had to cancel, I won't go into that here). They are very good, and certainly do not read from scripts.

In reply to a post by mixt:

The real downer here (and this is insane) is that BT will not allow you or your ISP to fixate (I think you mean) the target SNR for your modem sync - it just auto learns, and picks what it thinks is best.

On Orange's White Label BTW's 21CN WBC I can manually set my target SNR via my router (adslctl cmds). Is that what you are contending BT doesn't allow? How do you explain that I can do it? Or do you just mean that they don't allow the ISP to offer target SNR changes upon request, a l� Be?

In reply to a post by XRaySpeX:

I can manually set my target SNR via my router

I've often wondered how this actually works... obviously your router can't change the target SNRM in the DSLAM, I assume that the DSLAM asks your router what the signal level is and, if you've locally changed the target SNRM, then your router lies through its teeth... or is it done some other way that I haven't thought of?

I defer to a higher authority than I, Kitz, for any explanation.

That says how to do it, and is similar to the Billion 7800N (except that the 7800N fiddle will survive a reboot), but it doesn't say what it does... it's not really important, I'm just terminally curious

No, I was contending BT do allow it. Though this is a presumption. I managed to force sync at what ever target SNR I wanted using a SpeedTouch with Zen on a 20CN connection many years ago.

I presume it still works for the new 21CN connections too. BT probably allow it. What I was meaning was - it was my understanding that BT do NOT allow the ISP to fix the DLM at a static SNR, but as Roberto has pointed out, he seems to reckon this is incorrect. I only say this based on what AA said when I called them up.

Hard to explain what I actually meant. Two different situations.

1) The setting of the target (sync-time) noise margin on BT Wholesale circuits is within the BT Wholesale DLM. In the past that sometimes used to, maybe still does, get stuck at a high level after problems on the line. The DLM was/is expected to lower it over time, given a period of sufficient stability. BT Wholesale were able to reset it or in some way unstick it. ISPs have never had that facility, and most had extreme difficulty getting BT Wholesale to do it when needed.

It was the work of a few seconds .

ISPs now have access to a tool to set the target noise margin to the default 6dB, but this also redoes the initial 10-day training period. (There appears to be a delay in this happening after the ISP request - whether this is within an automated queuing system or whether it is a case of a BTW employee triggering it from a list of requests I have no idea).

That is fine so far as it goes, but can have a long-term detrimental effect if there is an ongoing problem causing low sync, as that low sync then becomes the maximum expected for that line, and 80% of that low maximum becomes the benchmark for even considering the possibility of a fault.

So, badly trained or deliberately misinformed support staff may, and certainly have done at times, inappropriately trigger this reset because of low speed. Whereupon the speed does not improve, but the line no longer has a reportable fault condition.

2) Given an unstable line with frequent disconnections, it has always been possible for the auto-adjustment of the target noise margin to be disabled, and the level fixed at any 3dB step up to (I think) 18dB, where the DLM peaked at 15dB.

I was under the impression this was done by Openreach engineers in order to correct the instability. To do this, it seems likely they had direct access to the DLM settings, similar to new ISP tool. Or maybe they had a request mechansim to BTW. One way or another it was achievable.

I seem to remember that occasionally ISPs have been able to get this manual setting carried out, but I don't think there was a formal mechanism.

The above sorts of thing are where AAISP are ace! Both in getting the correct settings applied, and in getting underlying problems fixed.