Noise Margin Dropping every evening

Altreab

Hello
I am monitoring my Router, a Netgear DG834G wireless modem. Its connected to computer using ethernet. During the day the noise margin holds steady at 17 or 18 db which is as good as i would expect since im approximately 4KM from the local exchange. However from about 3PM onwards it starts drifting downwards to a lousy 5db and less at around 8PM.stays under 10-12db until about 10 PM and then starts drifting upwards again overnight. Whats the most likely cause of this? My Sync speed is 1 Meg and upload speed is 128 kb.

MunsterCycling

Other users => contention on the line.

MC

Snaga

Its not contention - contention would affect IP throughput only - not SNR margins.

The likelihood is that you are on a long line that has many other DSL users in the same cable bundle on the way to the exchange. This causes interference which can introduce noise on your line, increasing the noise floor (and lowering the margin between signal strength and the noise floor).

This can sometimes be made worse by poor internal wiring - so its worth plugging the modem in at the first phone point in the house, disconnected all other internal wiring and monitoring it for an evening to see if its any better.

If its not - then there is little you can do - even changing to another DSL provider would not resolve the problem (Though an LLU provider _may_ provide a more robust signal strength using adsl2+). A wireless provider might be a better option if your looking for higher speeds than your currently getting.

crawler

As above and also...

There is no end to the things that can potentially impact your SNR - Sodium lights, dimmer switches even some children's toys!

If it is exactly the same time each day then it's very likely to be something on an automatic switch or timer, sadly this could be anything....but my guess is sodium lights close to your line outside, seems to fit the times mentioned. Can you follow your line?