Advice on extremely low noise margin

Router is plugged directly into master socket, there are no phones or other equipment on the line.

Line attenuation is 12db down 0.5db up

Noise margin up is 7db, but noise margin down hovers around 6db-4db and dips to -2db.

The router is losing sync every 2-3 minutes. Restarting usually re-establishes sync but it usually loses it again within 10 minutes or so. There have been sync problems on the line for around the last 5 days, and they've steadily been getting worse.

What steps do I take in fixing this? ADSL and phone service are through TalkTalk, do I call them? Or do I call BT because it looks like a line problem?

There have been high winds in my area over the last few days. The line looks clear up to the nearest telegraph pole, but lots of other lines in the area hit tree branches etc. and I noticed there are a couple of lose lines swinging from the pole.

Really need to get this sorted ASAP, any help appreciated. Thanks.

You call TalkTalk who handle all customer interaction and they fault find and arrange an Openreach engineer to look at the line if they feel there is a fault.

The 12dB down and 0.5dB attenuation up look odd too.

Avery strange set of figures ...

0.5 dB - even next to the exchange would normally get 2dB or more. Then with the noise margins - I would expect to see the UP figure being way more than 7dB and similarly with the down figures unless you are in a really "electronically" noisy area.

Can you check them again ...

Do you know how far you are from the exchange - straight line and by road?

Thank you both for your replies.

Here are the stats this morning.

http://i.imgur.com/jBsRtB3.png


Connection seems to be a bit more stable this morning, sync is holding with 6db noise margin.

Is it possible the problem is my router/modem? I've been using it for four or five years. Its awlays worked fine but these stats do look odd to me too.

Still a little odd.

Can you confirm how far from the exchange you are - a good approximation.

Very close - well under 1 mile.

Edit: google maps says 0.3 miles

Edited by deleted (Wed 17-Apr-13 12:35:28)

So 0.3 mile - that immediately tells me that the Upstream attenuation is wrong.

Is that straight line or an approximation of "by road"?

Maybe you need to record all your settings and do a full reset. Leave everything disconnected for 30 minutes if you do, three minutes is normally enough but I prefer a longer period so the DSLAM will start afresh when you restart.

0.3 miles is by road.

By a "full reset", do you mean a software reset of the router, restoring back to factory settings?

Or just turning it off and leaving it off for 30 minutes?

Thanks!

For full ADSL stats, switching off and a short wait to make sure exchange end has forgotten all about the connection.

A full factory reset and leave everything off.


I would expect to see the Upstream attenuation somewhere between 4dB and 8dB for that distance.

are there any extension wires or is it a "master-only" situation ?

Full factory reset, powered off for 30 mins with nothing else on the line, stats seem the same afterwards:

http://i.imgur.com/uOZgLFI.png

latency:

PING 8.8.8.8 (8.8.8.8): 56 data bytes
64 bytes from 8.8.8.8: icmp_seq=0 ttl=47 time=30.0 ms
64 bytes from 8.8.8.8: icmp_seq=1 ttl=47 time=30.0 ms
64 bytes from 8.8.8.8: icmp_seq=2 ttl=47 time=30.0 ms
64 bytes from 8.8.8.8: icmp_seq=3 ttl=47 time=30.0 ms

--- 8.8.8.8 ping statistics ---
4 packets transmitted, 4 packets received, 0% packet loss
round-trip min/avg/max = 30.0/30.0/30.0 ms

In reply to a post by yarwell:

are there any extension wires or is it a "master-only" situation ?

I haven't unscrewed the face place, but it's plugged directly into the main socket and I've tried a couple of different telephone cables, doesn't seem to make a difference.

You have a little more speed on the upstream but still that rather odd 0.5dB attenuation.

The downstream is looking reasonable.


Can you get a copy of Router Stats Lite and get that to plot the sync and SNR figures over a 24 hour period and then see how the margins vary.

if there are extension wires they can make a difference, give it a try in the test socket just in case.

OK, I think I have got router stats lite set up correctly and running and keeping a log.

Thanks again for your help. I will update this thread once I've collected some data.

I'd be looking at trying a different router first off.

Ran router stats lite for 24h or so, noise margin never changed from 6db, sync speed never changed from 19003.