A bit of a problem occurred with my internet setup this weekend. Basically, effective connection speed was very intermittent on my netgear router, even though sync speed was still it's usual 15M+. There's many different reasons for this, but after looking at the advanced router stats, it was obvious that I had a tremendous amount of noise on the line, CRC errors were about 80% of the total packet traffic and SNR had gone from approx 7.5dB to about 6.5dB (1dB of noise is quite a bit of
noise to an ADSL2+ connection!).
Noise on the line, again has many reasons, and can seriously affect ADSL2+, since it's sync'ing at much higher speeds typically than ADSL.
Testing the router directly in the BT test socket behind the master faceplate, it shot up to 10.1dB! A massive improvement, now with only about 0.5% CRC errors (which is good for a phone line).
So, looks like i've got a re-wiring job coming up. I've ordered a pre-filtered faceplate for both the master socket and the extension socket from ADSL Nation. These are pretty much the best you can get, and they remove the need for a "dangly" microfilter. I'll keep you informed.
Two posts ago, I mentioned I'd moved to using OpenDNS for my DNS resolution service, well, I've been experimenting tonight with dnsmasq, a local DNS cache which I'd heard good things about. Well, they're all true! Fantastic functionality. Basically, sudo apt-get install dnsmasq, configure /etc/dhcp3/dhclient.conf, /etc/dnsmasq.conf and the obligatory /etc/resolv.conf and you've got a local DNS cache! Now, instead of subsequent calls to OpenDNS taking about 35-40 msec, it now gets it in about 1 msec. Fantastic. If anyone's interested in doing this, then have a gander at http://www.ubuntugeek.com/local-dns-cache-for-faster-browsing-on-ubuntu-machine.html.
