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[guest]

I think Be support must have got the wrong end of the stick. You really don't want a 3dB profile. A 3dB profile will result in loads of errors if any noise spikes occur so you'd need a very quiet line for it to be worthwhile. Most people on Be who use the DMT tool don't understand this and tweak the SNR margin down to just above the point at which the line disconnects. This usually results in poor throughput speeds due to retransmissions - especially if Be have reduced the interleaving depth.

I think I'd rule out the old analogue phone idea, although it is a good one. The only reason I'd rule it out is that I've seen a few DMT graphs of Be lines which have been affected by them and it tends not to degrade the upstream. Reduced upstream is almost always related to wiring but this looks pretty drastic

[philangst]

Thanks Rizla.
Whilst I get another 2mb sync speed the connection drops at least twice a day so I think I will ask them to change the snr margin back to 6db. Not sure about less throughput but browsing seems slightly slower. I guess its a balancing act. I've given up with finding the source of the noise as I don't have the knowledge/inclination!

[guest]

Yes you'd probably notice it more with browsing - images missing until you reload the page etc? That's retransmissions caused by errors at the ATM layer. You've also probably tweaked your connection using DrTCP or TCPOptimizer as well which is recommended but when there's lots of errors on the line its actually better to have a smaller RWIN.

If I was you I'd ask Be to put you on a 6dB fully interleaved profile. Once they've done that then keep your connection up for a few days then post the DMT results here. Its possible that you can get a little more speed without dramatically increasing the errors.

I don't suppose you have another ADSL2+ capable router you could try? It is entirely possible that the power supply on the router is a bit dodgy - I seem to remember the wall plug runs quite hot?