cancel
Showing results for 
Search instead for 
Did you mean: 

Fantastic line stats, because of a fault!

David_W
Rising Star
Posts: 2,293
Thanks: 29
Registered: 19-07-2007

Fantastic line stats, because of a fault!

Insanity rules!  We have a line fault (major crackling on the line) which has dropped my speed way down (but this isn't about that so isn't for the other part of the forum) but my line stats stabilised perfectly, 29 attenuation with 9 SNR, perfect for getting 8Mb and actually better than before the fault developed (14 snr then!).
So how does that work?  My speed is down to 2.5Mb because of the fault, but my stats are great, so I thought 9 was a perfect snr (it's even dropped to 6!), so having a bad line gives better stats?  I would have thought that with a crackly line my attenuation would go through the roof and my snr would, actually I don't know what the snr would do!
Engineers just been here as I was writing this, and put in some device or another which means a reconnection, my stats:
Quote
DSL Connection Details
DSL Line (Wire Pair): Line 1 (inner pair)
Protocol: G.DMT
Downstream Rate: 7616 kbps
Upstream Rate: 448 kbps
Channel: Interleaved
Current Noise Margin: 9.0 dB (Downstream), 28.0 db (Upstream)
Current Attenuation: 29.0 dB (Downstream), 15.0 db (Upstream)
Current Output Power: 19.8 dB (Downstream), 12.0 db (Upstream)

All I got to do know is keep my fingers crossed that my snr sticks at 9 when the fault is fixed Cheesy
Out of interest, once the fault is fixed, any way for PN to manually reset my thingymabob, which has naturally dropped:
Quote
Current line speed:
3000
6 REPLIES
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Fantastic line stats, because of a fault!

We can manually amend it to match the BT one, although it should catch up automatically.
David_W
Rising Star
Posts: 2,293
Thanks: 29
Registered: 19-07-2007

Re: Fantastic line stats, because of a fault!

It looks fixed, waiting for engineer to phone and say its fixed, but again my stats get worse now that the line is better:
Quote
Current Rate: 7616 kbs 448 kbs
Max Rate: 7616 kbs 1112 kbs
Current Connection:
Current Noise Margin: 14.0 dB 28.0 dB
Current Attenuation: 29.0 dB 15.0 dB
Current Output Power: 20.0 dB 12.1 dB

Why does my SNR go to 14 when there is no line noise, but 9 when there is?  I thought SNR was supposed to be really high on noisy lines?
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Fantastic line stats, because of a fault!

That's a good thing!
Your SNR is higher because your sync speed can't go any higher (unless interleaving is removed).  A higher SNR is good on high synced lines.
David_W
Rising Star
Posts: 2,293
Thanks: 29
Registered: 19-07-2007

Re: Fantastic line stats, because of a fault!

Ahh I think I see.  if I went Fast Path my SNR would drop but I'd be at the full 8meg?
James
Grafter
Posts: 21,036
Registered: 04-04-2007

Re: Fantastic line stats, because of a fault!

If your connection remained stable, I'd expect it to stay similar.
For the benefits you'd get (minimal!), I wouldn't have thought it worth the risk.
David_W
Rising Star
Posts: 2,293
Thanks: 29
Registered: 19-07-2007

Re: Fantastic line stats, because of a fault!

I was put on fastpath not so long ago, but for some unknown reason a day or so later it had switched back to interleaved.  I still get pretty good download speeds so I'm happy enough with interleaved on, and eventually we'll be on 21CN so I should get pretty respectable speeds from that too.  it's still a mystery how my line stats were so good with a fault so bad it was almost impossible to hear what was being said on the phone.