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?

[Steve]

Certainly removing the bell wire reduces the interference induced into the adsl signal , I was looking a your stats posted earlier when you had a sync of 3008, somethings changed somewhere, can you carry on with routerstats overnight with the router plugged into the test socket with a fresh filter if you've got one.

[Swerv]

That sync speed was last night though Steve.  The connection has been out completely until late in the evening.  On that basis do you think that the sync speed could jump this evening?

Apologies if I'm being thick here, but is/can the sync speed be affected by interference?

I'll run the stats this evening again, certainly.  I've got Telnet running at the mo as well.  WRT to the Telnet stats, why would the upstream attenuation be double that reported on the router stats (28 vs 14)?

[Swerv]

Minor update:

Downstream NM has rocketed to 21db 

[Steve]

If it stays at 21db I suspect you've been placed on a banded profile although the sync you posted i.e 672 is not typical of an upper band limit, if routerstats is showing a constant nm of 21 I'd be tempted to try a resync as you've now got plenty of excess margin if the interference has now gone.

[Swerv]

Err, wow.  Just rebooted and:

ADSL Link    Downstream    Upstream
Connection Speed    4352 kbps    864 kbps
Line Attenuation    47 db    14.5 db
Noise Margin    5 db    11 db

[Simon]

That's some improvement! 

[Swerv]

A few graphs for everyones' delectation. 

[Rik]

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?

It can, but I'd check that you haven't loosened there wires on terminals 2/5 to be on the safe side.

[Rik]

A few graphs for everyones' delectation. 

I'd be inclined to try a 2-Wire 2700 router looking at that, <£20 delivered from eBay. Are all three graphs after the ringwire was disconnected?

[Steve]

Certainly seems to settle down around daybreak.

[Rik]

Which rules out the treadmill.

[Swerv]

Rik, all 3 graphs are from after removing the bell wire, yes.  

The graphs are taken from pretty much when I rebooted the router, following Steve's suggestion after I noticed the NM rocket.

I'll take a look at the router you mentioned.

[Rik]

Keep us posted.

[Swerv]

As an aside, is there any benefit to having an NTE5 fitted btw?  Or does the cost to get BT out to do it negate its worth?

Ooh, I just remembered, we have a couple of BT Homehub things lying around the office not being used....

[Rik]

There is, and it's often quite cheap to get BT to fit one, around £30. The problem is finding a sales rep who knows that.

[Swerv]

I have acquired a 2700.  Don't know firmware yet, but it's a dual SSID jobbie.  Can someone point me in the right direction as to where to go with this?  I've found various sites, but could do with one which runs from start to finish as to what I need to do.

[Simon]

Might be worth starting here:

http://www.idnetters.co.uk/forums/index.php?topic=8927.0

[Swerv]

Thanks Simon.

[Ted]

Or here. http://bt2700hgv.tripod.com/ir1002700HGV.htm

[Swerv]

Ok guys.  Got home and thought I'd check the stats.  Before doing so I setup the security on it.  It had been running without, as the Mrs' company laptop refused to connect.  She's since had a better WLAN utility installed by her IT team, in place of the bobbins Windows one.

Anyhoo, MAC filtering on and WPA-PSK.  These are the current stats:

ADSL Link    Downstream    Upstream
Connection Speed    3456 kbps    64 kbps
Line Attenuation    47 db    14 db
Noise Margin    8 db    8 db

Downstream NM is still all over the place.

So why on earth has the upstream sync plummeted? 

[Steve]

Is it  being reported correctly? Browsing won't be easy with such a poor upstream. The upstream tends to be less affected by noise as the frequencies used are lower. Any noise on the phone line, any broadband drops on phone calls? Have got another adsl filter to try?

[Swerv]

It's taking a while to load pages.  e.g. a good 10s to load all the smileys and icons that are present on the reply console on here.

But tested phone and no noise on the line, no broadband drops.

[Steve]

I think I'd see what support have to say tomorrow,

[Swerv]

Yep.  Will do Steve.  Just done a reboot and:

ADSL Link    Downstream    Upstream
Connection Speed    4224 kbps    864 kbps
Line Attenuation    47 db    14 db
Noise Margin    7 db    11 db

Frustrating.

[Steve]

It is as that looks fine, although when dealing with support (especially when faults are suspected), supporting BT speedtests are very helpful to them.

[Rik]

My first thought would be a noisy line or environment, Swerv. As Steve says, support will need some BT tests done. Can you borrow an alternative router to try?

[Steve]

Rik, Why on the last occasion do you think that the upstream has been hit so hard with the downstream spared?

[Rik]

It's inexplicable, Steve, unless the noise just happened to fall in that frequency range. Swapping routers at this point would be useful to eliminate that as a cause.

[Swerv]

I'm going to hook up the 2700 tonight guys.  Just interested to see what the stats will be when I get home first though.

Here's the NM from overnight.

[Rik]

That is ugly.

[Swerv]

Spoke to tech support again yesterday.  They'd spotted that generally things had calmed down a little, in terms of re-sync's, although there were still the odd ones the modem was doing.

Speeds have stabilised as well.  So they've reset the 10-day training period and hope that will stabilise the NM at nearer 10db.  Just going to leave it a few days now.  The NM looked a hell of a lot less ugly over the course of last night as well.

The only thing that worries me is that, on arrival home the last two evenings, my laptop hasn't been able to connect to the internet.  I'm connected to the router, and the router appears to be connected to the 'net.  I could only sort it last night with a reboot of the router, which I'm obviously keen to avoid.

Any pointers?

[Rik]

Try a cable connection. If that works, we need to examine your wireless setup.

[Swerv]

Hi all.  Tried cable connection this morning and no connection.  This despite the routerstats suggesting it is connected

Is this a stale connection?  Re-boot fixed it but obviously don't want to keep doing that.

[Rik]

It sounds like it, but it could be a router issue.

[Swerv]

Bit of an update for you guys.  A week before Christmas I spoke with tech support again and they said they could see the connection had been more stable, so they reset something (not sure what, as it wasn't the 10-day training).  What was interesting was they said the distance from teh exchange and general line characteristics meant that it was pointless us being on ADSL2+ as the line was only capable of achieving 3.5M on the ADSL connection.

They suspected that because the router was syncing at 4.5M it was causing a build up of errors which were forcing the router to drop the connection and re-sync at the low speeds.

Anyhoo, bearing that in mind, we've since had a stable connection at 5.7Mbps!  With NM of c6db.  The noise is still a little "changeable".  Definitely worse in the evening. 

Altogether though things are much happier though 

I must thank you all for you help over the last month.   

[Rik]

Our pleasure, Swerv. I wonder if BT have been working at your exchange?

[Swerv]

Well here's something interesting to ponder Rik.  Only a couple of days after the trouble first started, the other half got a call from BT asking whether we were happy with our current provider and service, and whether we'd be interested in moving across to BT.  They banged on about customer service and problem resolution etc.

As the trouble had just started the other half didn't say no but suggested they call back in a couple of weeks.  Their call back about whether we wished to switch occurred the day before the connection finally stabilised...

Maybe I'm just too cynical.

[Rik]

Or realistic.