SNR Help

CatMangler · Dec 22, 2011, 17:59:11

Hi,

I moved to Idnet back in November. All seems good, I'm on the ADSL premium package on my non-adsl2 exchange. With my previous provider I was lucky to get through-put anywhere near my sync speed. Previous sync speeds were 3 or 4 meg. Now I'm getting a rather alarming 7 - 8 meg with download rate to match!

Amongst other things I am a gamer and regard fastpath a necessity. Now that I am achieving this top sync rate my SNR has dropped through the floor to a value of 6 and with that the exchange is noticing re-sync's and errors and it moves my line to Interleaved.

I have contacted support but there is little that can be done from their end, is there anyway that my router or 3rd party app can be configured to help me sync at a lower rate to maintain a higher SNR thus keeping my fastpath connection?

I have 2 x ADSL routers :
Belkin 7633
DrayTek Vigror 2820n

Line stats:
Downstream Upstream
Data Rate(Kbps) 8000 832
Noise margin (dB) 6.2 11.0
Output power (dBm)12.4 19.8
Attenuation (dB) 39.0 25.0

Any advice would be greatly appreciated.

Rik · Dec 22, 2011, 18:03:30

Ask support if it's possible to have interleaving turned off. If they can still do this, and BT have been removing such powers from them this year, you'll get the lower latency, but at the cost of stability.

Glenn · Dec 22, 2011, 18:11:29

Is it still possible for BT to raise the target margin?

Rik · Dec 22, 2011, 18:17:33

I'm not sure, Glenn. So many tools have gone this year.

MisterW · Dec 22, 2011, 19:03:55

QuoteIs it still possible for BT to raise the target margin?

It is on a 21CN line. BT can set a fixed profile, which sets target SNR and Interleaving depth for Upstream and Downstream separately.
I have my line set at 6db and Interleaving off since I use Voip. Without the fixed profile the MSAN kept trying to drop the target SNR down to 3db to maximise the speed. I wanted more stability and definitely no interleaving.
I see catmanglet is not on a 21CN connection though...

CatMangler · Dec 22, 2011, 20:26:37

Quote from: Rik on Dec 22, 2011, 18:03:30
Ask support if it's possible to have interleaving turned off. If they can still do this, and BT have been removing such powers from them this year, you'll get the lower latency, but at the cost of stability.

Yeah thats has been requested and provided by support, however after a few weeks I eventually end up back on interleaved. In fact my SNR is now hovering around 3 - 4 at the moment. So am I buggered until BT find the time to upgrade my rural exchange?

I have been playing with my Belkin and I use to be able to set a target SNR through the CLI. Sadly this doesnt seem to have any effect any more.

Rik · Dec 23, 2011, 08:50:54

I'm afraid the answer is yes, and then some. Clearly DLM is kicking in to stabilise the line, and one of its tools is interleaving. Is Be LLU available at your exchange?

CatMangler · Dec 23, 2011, 09:00:12

Sadly the only LLU provider available on my exchange is TalkTalk

Rik · Dec 23, 2011, 09:02:40

Bugger. IDNet can provide a Telefonica connection (the parent of Be) in enabled exchanges. With those lines, they control the configuration, including fast path.

CatMangler · Dec 23, 2011, 09:08:41

Just a general question, why is BT removing the capability from ISP's to manage customers lines? Surely it gives the customer a better service if they could.

Rik · Dec 23, 2011, 09:10:26

I think BT are trying to give their own services an advantage, tbh, because they can still tweak.

CatMangler · Dec 23, 2011, 11:53:48

That kinda stinks of unfair competition, oh well should have stayed where I was. Live 'n learn I guess