2.9 dB noise margin, good or bad?

[pctech]

Now synching higher than ever at 4335 Kbps  with 3.6 Mbps throughput and noise margin is 2.9, is that good or bad?

[lozcart]

On a good line BTs line management will normally drop your target noise margin down to 3.0. It would seem that is what yours is set to Mitch, the router is now indicating 2.9 which means it has picked up a little more noise but nothing to worry about. If it stays around this level then you should hold that sync fine.

[Lance]

I can't add to that. I'm fortunate enough to have the 3db noise margin too.

[JB]

I find some of this hard to grasp. I have a pretty good line and am only about 1.5km from the exchange. I sync at 8128 Kbps and my SNR margin varies between 7 and 9 dB depending on the time of day. I'm guessing that because I sync at the maximum speed for vanilla ADSL the exchange sees no need to try to adjust the margin ?

[Steve]

Sort of right, the local DLM probably gives your line the default margin of 6 but you've got room to spare overhead which works out for the router/modem at 9. I used to have a full sync with a router stats downstream margin of 13 on adslmax. It also means you get a stable connection as it takes a fair bit of noise to upset the DLM. Obviously things would change with adsl2+

[JB]

Thanks for the info Steve, appreciated.

Our exchange is located in rural Cheshire with only about 1200 phone subscribers and even less ADSL users. Sam Knows shows no plans to give us an upgrade to ADSL2+ and 'fibre' is a word in a foreign language here 

[pctech]

Excellent, the two BT visits have been well worth it then