Speed drop

I have upto 20Mbps and having been getting a speed around 12Mbps (down) and 1Mbps (up) for the last two months with a Netgear DG834 v4 wired adsl/router. A sense of adventure drove me to try the Home Hub 2 that was sent to me when I signed up for the up to 20Mbps service, and the same speed was maintained after I installed it.

Two days after switching to the Home Hub it blew up - well, stopped working - and after a helpful session with BT they sent me a new HH. While I was waiting for the HH to arrive I went back to the Netgear and found that my speed had dropped to around 10Mbps. This same lower speed was achieved when the replacement HH was installed. This evening, my average speed is around 8Mbps.

and... connection sync speed is 13.3Mbps down and 1.1Mbps up. Noise margin is: 8.6dB/6.0dB. Line attenuation is 26dB/12.7dB

Grateful if someone could explain to me what is probably happening and what the prognosis is. Thanks.

Edited by chucklesdad (Tue 02-Mar-10 22:50:09)

I expect if you check the stats immediately after a reconnection the noise margin will be 9dB, whereas before the HH blew up it was probably 6dB. That can cause a connection speed loss of over 1Mbps and an even greater fall in download speed due to the BT DLM system.

See DLM, IP Profile, and Troubleshooting >> High Noise Margin (Section 4) pages on my website.

With luck keeping a stable connection for 10-14 days will cause the DLM to lower the connection time margin to 6dB.

Thanks very much for your reply. I'll follow up as you suggest and keep my fingers crossed for a return to higher speeds.