Author: Paul Stimpson Date: To: Hampshire LUG Mailing List Subject: Re: [Hampshire] Fw: ADSL Line problems
Hi,
An ADSL signal isn't one signal. It's a large number of different-frequency slow signals (about 2000) called "tones" that get joined together to look like one fast signal.
On most lines some of the tones won't be usable because of the condition of the line or interference. For example I get about half the tones on mine so I get 4MBPS out of the "up to 8" ADSL Max gives.
If too many tones suffer errors suddenly the modem will lose synchronisation and have to connect again.
ADSL has a thing called DLM (Dynamic Line Management). DLM counts the number of disconnections and knocks out groups of tones that are making it fail. If the quality of your line has improved (as is indicated by the much higher speed) and you're getting lots of disconnections it looks like DLM has detected the new usable signals and cranked the speed up a bit too far. There is a lag built in so temporary things like interference from a car with a bad ignition outside don't force a change in your speed.
It may take a week for DLM to go through and find the right settings so your line stabilises so I'd wait til next weekend before risking a £169 callout fee for getting BT in if there's nothing wrong.
I would recommend a filtered faceplate and pro modem cable from ADSLNation.co.uk as these are better than normal ADSL filters and may well help things settle down.
Is there new firmware available for your router from the manufacturer's support site? If so it may improve things.
