Connection Issue - Interference?

[Swerv]

Hi guys.  Having some trouble over the last couple of weeks with the route not being able to connect until late in the evening (like now!)

Quite often when it has come on in the evening it's been connected until the following morning.  Return from work and it's gone again.

I've been on to IDNet who've looked at the line and suggested everything looks fine.  I've been trying it with 2 Netgear routers and at first they suggested it could be both routers that were goosed.  But given the timings they're leaning towards an interference issue.

I've bought a MW radio to try and pin down any electrical interference but can't find anything in our house that affects it, so I guess I'll have to knock on the neighbours next.

Is there anything else I can do to pin this down?  Or are there routers available that are better protected from interference?

Or, could it be something else entirely do you think?

[Simon]

Is it that the router won't connect to the Internet, or can you not connect to the router from your PC?

[Swerv]

Router to internet.  Connecting to router no problems.

[Simon]

Can you post your router stats, then someone should be able to help you.  Also, it might be worth running the RouterStats program for 24 hours, which might give an idea as to what is happening. 

[Swerv]

No problem Simon.

These are the stats from the router currently plugged in (DG834G), which is newer than the other one that's generally plugged in.

ADSL Link    Downstream    Upstream
Connection Speed   2624 kbps   832 kbps
Line Attenuation   47.0 db   29.0 db
Noise Margin   11.0 db   11 db

[Swerv]

Wha's the routerstats program?  Both our machines are company laptops so aren't at home all day to record info, assuming that's what the program does?

[Rik]

It does, but as the problem occurs when you're at home, running it then would be adequate.

http://www.vwlowen.co.uk/internet/files.htm
http://www.vwlowen.co.uk/moreinternet/files.htm

is where you'll find it.

Your sync speed is low for your attenuation, but that looks to be due to having a target noise margin of 12db from the look of things. If you can get the line stable, and the target NM drops back to 6db, then you'd gain about 1-1.5M.

How's the router connected to the phone line (say a wire and I'll sulk! ) Is it at the master socket, or run from an extension? Do you have hard-wired extensions, in which case have you checked for the ring wire being connected, terminal 3, at each socket. You don't need it and you don't want it. The only connections needed are terminals 2 & 5. Make sure they are a pair, eg blue/white & white/blue.

What else is connected to the line, and, if it includes a DECT phone, where's the base station, and what brand is it. Have you tried changing the filter, and using a screened lead from phone socket to router?

Sorry, I always answer a question with a bunch of questions.

[Technical Ben]

I think we need a little handy check list for that one Rik. But nice job none the less! 

[Rik]

Thanks, Ben.

[Swerv]

Your sync speed is low for your attenuation, but that looks to be due to having a target noise margin of 12db from the look of things. If you can get the line stable, and the target NM drops back to 6db, then you'd gain about 1-1.5M.

This may be due to the router that's attached.  A few months back I was having trouble in the flat I was in with the very same router with the NM.  I'll hook the old one back up tonight and see how that goes on.

How's the router connected to the phone line (say a wire and I'll sulk! ) Is it at the master socket, or run from an extension? Do you have hard-wired extensions, in which case have you checked for the ring wire being connected, terminal 3, at each socket. You don't need it and you don't want it. The only connections needed are terminals 2 & 5. Make sure they are a pair, eg blue/white & white/blue.

Router has been moved downstairs to the master socket.  We have hard-wired extensiosn yes but I've never checked what's connected.

What else is connected to the line, and, if it includes a DECT phone, where's the base station, and what brand is it. Have you tried changing the filter, and using a screened lead from phone socket to router?

There is a DECT phone hooked up yes, an old BT jobbie.  I actually disconnected it yesterday, as the base station is also connected to the mastersocket.  I have changed filters yes.  Tried three different types, but no I haven't used a screened lead.

Sorry, I always answer a question with a bunch of questions.

No problem!

I would add that in three years we haven't ever had a single period of not being connected (at least not that we've known about).  The older Netgear router usually sits upstairs, connected to one of the hardwired extensions.  So if it is interference, it's affecting it all over the house it would seem.


[/quote]

[Rik]

This may be due to the router that's attached.  A few months back I was having trouble in the flat I was in with the very same router with the NM.  I'll hook the old one back up tonight and see how that goes on.

It will take about 15 days of stable connection before the target NM will drop.

Router has been moved downstairs to the master socket.  We have hard-wired extensions yes but I've never checked what's connected.

Take a look. If the ring wire is connected, removing it can have almost miraculous results. The ring wire, being unbalanced, ie a single wire, acts as a giant antenna for RF noise.

There is a DECT phone hooked up yes, an old BT jobbie.  I actually disconnected it yesterday, as the base station is also connected to the mastersocket.  I have changed filters yes.  Tried three different types, but no I haven't used a screened lead.

Try one, they can help in electrically noisy environments. PC World if you want to pick one up locally, or ADSL Nation online.

Try moving the DECT base station to the 'remote' socket and double filter it.

I would add that in three years we haven't ever had a single period of not being connected (at least not that we've known about).  The older Netgear router usually sits upstairs, connected to one of the hardwired extensions.  So if it is interference, it's affecting it all over the house it would seem.

Two frequent causes of high levels of interference are bad Sky boxes, I know of one case where one put so much noise on the line that it took out several houses, and electric treadmills.

[Tacitus]

It will take about 15 days of stable connection before the target NM will drop.

I think there's a bit of voodoo in it Rik.  After 30 days of a solid connection I needed to reboot my router and expected the target SNR to drop from 15 to 12.  Made absolutely no difference to the SNR, but the connection speed dropped slightly.

Isn't BTs DLM wonderful....   

[Rik]

Probably errors on the line, in some situations, BT won't accept a single error, Tac.

[Tacitus]

Probably errors on the line, in some situations, BT won't accept a single error, Tac.

My reward for an 'engineer's visit'.   Although it's stable it's slower due to the multiple re-syncs when he was doing the testing.  I thought it would recover, but apparently not....

[Swerv]

WRT to the ring wire, I've now removed from the extension socket.  Does it need removing from the main socket?

Came back on about 20 minutes ago btw.

Current stats, from the older Netgear router:


ADSL Link    Downstream    Upstream
Connection Speed    3008 kbps    800 kbps
Line Attenuation    41 db    14.5 db
Noise Margin    12 db    11 db

I'l get the routerstats program downloaded and running

[Swerv]

What sort of stats would be useful to you guys from the Routerstats?

[Steve]

You just need to monitor the downstream margin with routerstats and yes the ring wire does need to be disconnected from the master socket.

[Rik]

What Steve said, Swerv. The graphs from Routerstats will tell us a lot about what is happening. I'm encouraged by the apparent speed improvement so far, get rid of the other end of the ringwire and see what that does.

[Swerv]

Cheers guys.  I'll remove the ring wire tonight then.  Anything I should do when I do so?  Or just literally disconnect from the terminal and fold out of the way?

Here are the downstream NM stats.  I left it on overnight.  The router was still connected to the internet this morning when I left.

[Rik]

Gently lift it out of the terminal with a pair of pliers and curl it up.

You're showing a 3db noise swing, -2db at night, +1db during the day. That's pretty much to be expected and there's no reason why your line shouldn't operate on a 6db margin, depending on the error count. Those short pulses, though, suggest something is switching on and off.

[Steve]

Interested to see if those spikes disappear once the ring wire is disconnected from the master socket

[Rik]

It will, Steve. My own margin variations, though similar in dimension, ie +1/-2, are much more of a 'smooth' pattern across the 24 hours.

[Swerv]

Right, bell wire disconnected.  We went from no connection to connection.  Which is something.

Stats are:

ADSL Link    Downstream    Upstream
Connection Speed    672 kbps    800 kbps
Line Attenuation    43 db    14 db
Noise Margin    13 db    11 db

So sync speed has plummetted, presumably because the interference is still there, just we're better protected against it now?

[Steve]

Not sure what's going on there , removing the bell wire shouldn't have hit your downstream sync like that.

[Swerv]

Well it wasn't connecting at all until I removed the bell wire.  So can removing the wire have reduced the susceptibility to interference enough such that it is now able to connect but just not at a decent speed?