Any idea why my Noise Margin would suddenly leap up?

[Rik]

It has to be possible, Jonathan. Until BT tell us what the fault is, exactly, no-one can be sure.

[PuncH]

Well, after a lovely evening of full internet access following the apparent "fix" of the Peterborough issue my line briefly dropped again this morning.

I didn't see the big increase in noise margin this time, which was nice but I took the oppotunity to try the BT test socket.

I get exactly the same sync speed and noise margin using the test socket, so does that rule out any of my equipment being faulty inside my house? (ie...router)

[Rik]

Yes.

[PuncH]

Yes.

Whoopee!

Once my new filter and shielded twisted pair ADSL cable arrives from ADSLNation I shall swap back onto the normal socket and then see how things go. Support have said they can get my line retrained so hopefully I'll get back to where I was speedwise just before all this trouble started. If not, then there must be a small problem on my line somewhere.

You know, I'm sure I heard some crosstalk when I was on the phone the other night 

[Rik]

 

[PuncH]

Posty has just been and delivered my ADSL Nation goodies, so they are now installed.

Fingers crossed for when IDNet reset my profile and take off super stable! 

[PuncH]

Instant improvement on the upstream noisemargin. It was 10.x db this morning and had a sync of 888kbps.

ADSL Link             Downstream  Upstream
Connection Speed  9727 kbps    1244 kbps
Line Attenuation    15.5 db        6.2 db
Noise Margin          24.3 db       6.5 db

Would I be wrong to be hopefull of regaining my old speeds of 17500 downstream once my profile is reset?

[Glenn]

 

[Simon_idnet]

Hi PuncH

Your Profile is dependent upon the Connection Speed which is dependent upon the Noise Margin. If the Exchange sees that the interference on your line has reduced then it will reduce your Noise Margin back down towards the target 6dB. As the Noise Margin reduces then there are more available frequencies for your router to use for bandwidth and so your Connection Rate will increase. If your Connection rate increases then so will your Profile which will then provide you with a higher throughput.

Regards
Simon

[PuncH]

I switched my router off last night in an effort to help things out...bad idea.

Now connected at 5200 with a noise margin of 30!

Been on the phone to Miriam this morning who has said to wait till the Peterborough BRAS issue is properly sorted, and then they will look at my line because it's likely all the ups and downs/dropouts etc over the last 3-4 weeks have not helped at all.

[Steve]

You could well have ended up with your profile being banded by BT due to the  Peterborough issues and the noise margin of 30 now shows the potential for future gains after  they've sort it out.

These are taken from the plusnet forum, So if interleaving and an increase in your target SNR doesn't stabilise the line the DLM will band your profile so you sync within certain limits

WBC banded line profile (rate kbps)
7168 - 14336
4864 - 9728
3328 - 6656
2272 - 4544
1472 - 3072
1152 - 2272
576 - 1152
288 - 576
160 - 288

[PuncH]

I've been seeing daily re-syncs, just once, in the morning since the Peterborough thing started and these re-syncs are what has killed my speed.

Would I be right in thinking the re-syncs are a response to the previous nights ups and downs etc? I've just realised they did stop for 3 or 4 days around Christmas which is also when there were no issues with the Peterborough BRAS.

If so, I look forward to the day BT fix the damn thing!

[Rik]

It's hard to say, Jonathan, but it's a possibility.