High target SNR - line retrain

btb · Oct 21, 2006, 09:47:43

Due to a combination of poor internal wiring/poor quality filter and a series of thunderstorms several months ago my target SNR was automatically increased to 9dB. I've since replaced the filter and wiring and now have far better set up than when I first got ADSL Max in April.

The problem is my line was originally trained before I made the improvements, and then the target SNR was upped to 9dB. It seems pretty impossible to get BT to agree to a new training period, mainly because it needs BT to actually acknowledge it as a fault, and then get someone clued up within BTw to get involved and arrange the retraining period.

There is a theory that by migrating the line back to a fixed rate connection all training data will be removed, so that by then upgrading back to the MAX product a new training period would be started. Does anyone at IDNet know if this the case?

I would really like to get my line back to performing at its current capabilities. An increase target SNR from 6dB to 9dB might not sound like very much, but I have taken the trouble to improve my connection and would like to reap the full benefit by getting back to 6dB. I can use the DMT tool, but would really like a more permanent solution.

So, does anyone know if migrating to a fixed rate product then upgrading back to MAX will wipe the slate clean and trigger a new training period and new MSR?

AndyG · Oct 21, 2006, 11:42:35

Hi

I did this a couple of weeks ago. Changed back to Home 2000 for a fortnight and then regraded back to Home Max. I've just, (this morning in theory), finished my new 10 day training period and have a 6db noise margin.

Andy

maxping · Oct 21, 2006, 11:53:47

Quote from: btb on Oct 21, 2006, 09:47:43

So, does anyone know if migrating to a fixed rate product then upgrading back to MAX will wipe the slate clean and trigger a new training period and new MSR?

Simon from IDNet reads the boards here so you may get an official response over the weekend , if not give customer support a call on Monday, you wont be kept hanging on the line listening to cr*ppy music like most other ISP's Customer Support.

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btb · Oct 21, 2006, 12:23:36

Quote from: AndyG on Oct 21, 2006, 11:42:35
I did this a couple of weeks ago. Changed back to Home 2000 for a fortnight and then regraded back to Home Max. I've just, (this morning in theory), finished my new 10 day training period and have a 6db noise margin.

That is a very encouraging reply. So before you had a target SNR higher than 6dB?

Quote from: maxping on Oct 21, 2006, 11:53:47
Simon from IDNet reads the boards here so you may get an official response over the weekend , if not give customer support a call on Monday, you wont be kept hanging on the line listening to cr*ppy music like most other ISP's Customer Support.

Thank you. I'll keep an eye on this thread, I'm not in a hurry and the answer might be useful for other people in the same situation too.

Lance · Oct 21, 2006, 13:10:19

and maybe the question and answer could go in the faq?

AndyG · Oct 21, 2006, 21:48:06

Quote from: btb on Oct 21, 2006, 12:23:36
That is a very encouraging reply. So before you had a target SNR higher than 6dB?

Yep, the combination of dodgy router firmware and the thunderstorms of a while back put me on 9db and interleaved. Interleaving was easy to get removed but, as you found, there is no way of getting the noise margin reset. Going to Home 2000 for a fortnight gave me a 'clean sheet' and a fresh 10 day training period when I returned to Max.

Andy

btb · Oct 22, 2006, 06:25:46

Quote from: AndyG on Oct 21, 2006, 21:48:06

Yep, the combination of dodgy router firmware and the thunderstorms of a while back put me on 9db and interleaved. Interleaving was easy to get removed but, as you found, there is no way of getting the noise margin reset. Going to Home 2000 for a fortnight gave me a 'clean sheet' and a fresh 10 day training period when I returned to Max.

Thanks AndyG for confirming the details. I've been on a mission to try and get this confirmation from someone who has done it.

Did you decide to wait for 2 weeks or were you advised it would take that long for BT to clear down their records held against your line? Sorry to keep asking you questions, but I've been looking for someone who has taken route this for months, and just want to try and answer as many of my questions as I can!

My present ISP don't do a fixed rate product, and have said that they believe BT keep the records for your line even if you do go back to a fixed rate, meaning that when you upgrade back to Max again you will be in the same postion as before. So thanks again AndyG for providing evidence that in your case it did wipe the slate clean.

I'm just waiting for a MAC to be issued and it looks like I'll then be heading this way. The plan will be to migrate onto 2Mb fixed rate then upgrade to Max once my line details have cleared down. Seems like I will have found a good ISP to join even if I didn't need to get my line retrained.

TimJ · Oct 22, 2006, 10:08:27

If you hold a good enough sync for long enough the target SNR will reduce by itself.

Three weeks ago I changed router and I can now hold sync far better than previously and a week ago went from 15dB to 12dB.

I am just waiting to see if it drops further.

Tim.

AndyG · Oct 22, 2006, 10:20:44

Hi

I have no first hand experience but I have read on ADSLGuide that when you change ISP you get a new training period anyway. A mail or call to IDNET should confirm this either way - IDNET's Customer Services are really as good as they say.

I'd heard that 14 days were needed for the profile to clear mentioned somewhere so just opted for that period. To be honest, I didn't really notice any great difference between 2 Meg and the circa 5 Meg I get with Max other than I just had to wait a little longer for the odd thing I download to finish so it wasn't too great an inconvenience.

Andy

btb · Oct 22, 2006, 12:20:06

Quote from: TimJ on Oct 22, 2006, 10:08:27

If you hold a good enough sync for long enough the target SNR will reduce by itself.

Three weeks ago I changed router and I can now hold sync far better than previously and a week ago went from 15dB to 12dB.

I am just waiting to see if it drops further.

Its good that you got the reduction from 15dB to 12dB. I've been syncing at a high stable rate for around 5 months waiting to drop back to 6dB, just doesn't seem as though it's going happen on its own.

Quote from: AndyG on Oct 22, 2006, 10:20:44

I have no first hand experience but I have read on ADSLGuide that when you change ISP you get a new training period anyway. A mail or call to IDNET should confirm this either way - IDNET's Customer Services are really as good as they say.

I'd heard that 14 days were needed for the profile to clear mentioned somewhere so just opted for that period. To be honest, I didn't really notice any great difference between 2 Meg and the circa 5 Meg I get with Max other than I just had to wait a little longer for the odd thing I download to finish so it wasn't too great an inconvenience.

Thanks for taking the time to explain, appreciated. I'll call and speak to CS on Monday and see what the official line is.

Cheers!

AndyG · Oct 22, 2006, 13:45:29

Quote from: btb on Oct 22, 2006, 12:20:06
Its good that you got the reduction from 15dB to 12dB. I've been syncing at a high stable rate for around 5 months waiting to drop back to 6dB, just doesn't seem as though it's going happen on its own.

It is my understanding that you have to stay connected without any disconnections or retrains for over 3 weeks for the noise margin to drop one 3db step. Some people on ADSLGuide seem to have achieved this but I think they are very few and far between. I now have my connection pretty stable but I still get the odd spontaneous retrain from time to time - the longest uptime I've achieved up to now on a 3km line is something like 10 days.

Andy