Training History Problem

Sebby · Jan 13, 2008, 12:50:15

I'm having some trouble of late, whereby IDNet are getting my target SNRM reset to 6dB, then I have a single resync in say 2 days and my target SNRM shoots back up to 15dB. I don't think this is to do with the 2Wire itself, but it's training history is bizarre.

I go to http://192.168.1.254/tech then look at DSL Diagnostics. What's strange is that the times and dates of the retrains are wrong. The last retrain always shows as the current time and date, depending on when I log in. This is making it difficult to see what's going on (i.e. when my router retrained).

If you look at the attached picture of the training history, you'll see that the first train was on January 10, which is incorrect. In fact, January 9 was the first time my router retrained and sync'd at 15dB, so I'd actually unplugged the router and plugged it back in to see if this cured the issue (which it didn't) hence no prior history.

The next one, showing as January 12, is when IDNet requested that my target SNRM was dropped to 6dB. This in fact took place on January 10, not January 12.

The last resync occurred last night at some point, but I don't know when as it always gives the time and date as when I logged into that page on the router!

The whole thing with the SNRM dropping following a single resync is beyond me, but it would be much easier if I could see precisely when it's occurring.

Thank you in advance.

[attachment deleted by admin]

Rik · Jan 13, 2008, 12:56:57

The second, or last, figure always show when I access the page, Sebby, while the earlier ones seem to indicate re-trains since re-boot. I don't suppose the date in the router is wrong (hear the sounds of straws being clutched?).

Sebby · Jan 13, 2008, 13:04:44

The time and date is definitely correct, Rik. It's the first thing I checked (I should have mentioned that!).

I love this router, but the one thing I found strange is it's reporting, not just of the training history.

What's the logic in it giving a fictitious time/date? Surely it must know the actual time/date when it retrained?

Being the technical genius that you are, Rik, what do you think about this ridiculous problem with the targeting SNRM reverting back to 15dB following a single resync?

Rik · Jan 13, 2008, 13:08:16

It sounds like the DLM software has still got the line tagged as unstable - but that's just an opinion. IDNet will be able to find out for sure.

Sebby · Jan 13, 2008, 13:13:37

Okay, thanks, Rik.

I can't understand why a resync is occurring in the first case, either. My SNRM is always above 6dB, and the noise problem that I had a little while ago has definitely disappeared. I'm wondering if this is being caused by something at BT's end as well.

Anyway, like you say, IDNet should be able to find out more.

As always, thanks for your help, Rik.

Rik · Jan 13, 2008, 13:19:21

I have found that my 2700 will re-sync at a 5db margin, Sebby, so perhaps yours is doing something similar? What was the margin showing in the second entry of the second line?

Sebby · Jan 13, 2008, 13:24:48

I'm certain that's not the case with mine, Rik, as when I was first reset back to 6dB, I saw it go as low as 4dB (because BT had reset it in the day, and it obviously degraded come night). After that, I manually resync'd at night so the worst it was ever getting was 6dB, and it was 7-8dB in the day.

To answer your question, mgn 1 is showing as 9.0 and mgn 2 as 7.0

Rik · Jan 13, 2008, 13:26:44

The 7 is the figure at which it re-synched, to judge by what I've seen here. Perhaps BT were kicking the tyres again?

Sebby · Jan 13, 2008, 13:44:38

It seems too much of a coincidence. It's happened at around the same point (I think just short of 2 days sync) both times that my margin has been reset.

Ted · Jan 13, 2008, 14:41:15

I had a resync at 5.31 this morning for no apparent reason. I know this from scouring the detailed log.
If you look at the pic you can see the time shown above the current time is the time it reset.

[attachment deleted by admin]

Rik · Jan 13, 2008, 14:44:46

It certainly wasn't a margin drop in your case, Ted. It's a shame that the router (or any router) doesn't record a cause against the re-sync - it could save a lot of guesswork.

Ted · Jan 13, 2008, 14:51:04

OOOOOOO that would be handy

Previous to that pic the router held sync for over 20 days with a stable margin, around 12. Then early one morning it resynced and the margin recorded was 5. The router auto resynced straight away and did so at 12 ?

Rik · Jan 13, 2008, 14:57:55

That's the same pattern I see, Ted - often with an increase in sync speed. Makes no sense. $:-\$

Ted · Jan 13, 2008, 15:12:10

I use BT firmware and you use SBC so that can't have any bearing on it. To be honest its not a problem as i always seem to sync back to 7616, so no harm done

Rik · Jan 13, 2008, 15:13:38

You're right, I still sync higher than the Netgear ever did, and the margin is stable the rest of the time. It would be nice to know what happens, though...

Ted · Jan 13, 2008, 15:30:26

Clip from the log at time of resync. Doesn't show much at all

[attachment deleted by admin]

Rik · Jan 13, 2008, 15:34:20

Quote from: xild on Jan 13, 2008, 15:30:26
Clip from the log at time of resync. Doesn't show much at all

No, the usual bald statement of fact - no use to man nor beast.

Ted · Jan 13, 2008, 15:42:57

Quote from: Rik on Jan 13, 2008, 15:34:20
No, the usual bald statement of fact - no use to man nor beast.

No use to me either

Rik · Jan 13, 2008, 15:47:50

Well, I was honest enough to include beast for me.

Sebby · Jan 14, 2008, 19:44:58

I had a very comprehensive email from James today. BT had said that the DLM was increasing my target SNRM because of an excessive number of errors. Usually I wouldn't believe them (BT), but when I was with Entanet previously, I had throughput issues when my target margin was 6dB, and BT said it was high errors (although, surprisingly, the DLM didn't increase my margin then). I didn't realise that the DLM would increase your target SNRM due to a high number of errors when it's not causing instability, but there you go.

Thankfully (I suspect largely due to the technical ability and care employed by James) BT agreed to set my target SNRM at 9dB, which should hopefully put an end to this problem. I used to be on 9dB anyway, and in some ways I prefer it as it gives that bit more comfort.

I came home to find the 2Wire sync'd at 4.9Mb @ 8dB. I was happy because that's still enough sync for a 4000k profile (with a target SNRM of 6dB, I only had a profile of 4500k, so no great loss at all).

What's funny is that my SpeedTouch 585v6 struggled to get anywhere near 4.5Mb @ 9dB - and I often had to resync a number of times to try and get enough sync for a 4500k profile - so the 2Wire really shines. I rebooted so that I had a SNRM of 9dB at night, hence it should never go lower than this now, hopefully keeping those errors down. The 2Wire still got a plenty high enough sync for a 4000k profile (about 4.7Mb, IIRC).

Ted · Jan 14, 2008, 21:04:42

Sounds like a result to me.

Sebby · Jan 14, 2008, 21:09:34

Well I certainly hope so. At the moment I'm happy as can be, so let's hope the DLM do the dirty again.

Rik · Jan 14, 2008, 23:03:57

I also went to a 9db margin, Sebby, and it's given me a reasonably stable line, eg 2 re-syncs/month. I suspect interleaving will also be on (on your line, it is on mine), improving the error handling. The only time I'm really aware of the difference in speed is on a large download, but then I now make those without lost of grief, so it was a fair trade for me.

Sebby · Jan 14, 2008, 23:18:50

I believe interleaving was always on. To be honest, I doubt I'll notice any difference. I'm very happy with a 4000k profile if my line is stable. A lot of people try and squeeze everything out of their line at the cost of stability. IMHO, stability is almost as important as speed.

Rik · Jan 14, 2008, 23:21:15

That was certainly my decision, Sebby. I've got things to the point where I have reasonable speed and good stability. I'm also getting between 2.5 and 5x the speed that my neighbours achieve.