ADSL2+ Reliability Problems

JamesAllen · Nov 07, 2010, 11:46:19

Hi guys,

I have contacted support on this but thought I'd throw it up here as well in case you guys can give me some insight while I wait to hear back.

I had my connection activated on Thursday and everything has appeared to be running properly - sync looks good, transfer rates are as expected and the BT speed tester is showing exactly what it should do.

However, yesterday afternoon and early this morning my router seemed to lose the ability to get to the default gateway.

At these points, the router shows that it is fully connected without any errors. It just stops being able to get to the default gateway (212.xx.xx.xx).

As soon as I reboot the router and the connection is renegotiated everything works as normal.

Is there anything that might suggest what the potential issue is?

My router is a brand new Netgear DG834G v4 although I only bought it recently for this new connection so it isn't time proven as of yet. I can run any diagnostics via telnet if there are stats I should grab during the next failure.

Current connection stats:

ADSL Link
Connection Speed
Line Attenuation
Noise Margin

Downstream
14962 kbps
25.0 db
6.1 db

Upstream
1152 kbps
11.1 db
6.1 db

Not sure if this is relevant but this morning when I got up and noticed the problem, my downstream sync was a little over 15000kbs and downstream was around 1000kbs.

The connection problems seems to have started yesterday as the router was fine before this and went live on Thursday at 2am ish.

Thanks in advance.

Steve · Nov 07, 2010, 11:52:19

Not using a Netgear at present so terminology will be wrong, there's not a disconnect when idle option set incorrectly?

Rik · Nov 07, 2010, 11:57:28

One other possibility is that the router is in sync, but losing PPP. BT are doing a lot of engineering work, locally and nationally which might cause such a condition.

flinty · Nov 07, 2010, 12:15:19

I have had similar 'symptoms' for the last few days, full sync but unable to access any sites. Have had to disconnect and reconnect, and probably as a result my sync rate has dropped from about 11,000k to 6,000k. I have put it down to BT activity as there seem to have been a few Openreach vans around recently.

Hopefully if it settles for a few days, sync will get back to normal

Steve

Rik · Nov 07, 2010, 12:17:10

There's a massive raft of planned work in connection with 21CN, Flinty. I think I'm down for this coming week.

zappaDPJ · Nov 07, 2010, 12:24:55

That's quite interesting. I've recently had a lot of DNS type issues but no loss of sync (in the North London area). I thought I was the only one. A modem reboot sometimes allows me to get to the odd site, perhaps 1 in 10. As Rik says, it could be planned work on the infrastructure.

Technical Ben · Nov 07, 2010, 13:26:32

Is that with multiple DNS settings (IDNet versus Open DNS for example?).

JamesAllen · Nov 07, 2010, 13:27:50

Thanks for the replies guys.

I hope it is only temporary as it's a little unsettling having only just moved over and already having 2 outages. Hoping it's not my router which is at fault, though if some of you have had similar issues recently then maybe it is with BT.

I never lose sync though, just connecting to the default gateway. No problems are noted on the router logs and the connection status states it's connected fine.

Just annoying when it happens over night as it can impact downloads etc.

Have to see how it plays out and will see if support can offer any suggestions specific to my exchange etc.

Just thinking that maybe I could look at writing a script to check the default gateway every 10 minutes. If there is a ping timeout I could then maybe initiate a router reboot if I can find the correct URL to cause this or maybe write a telnet script. Bit of a hack but if it turns out this is just BT maintenance then it would be nice to have a fail safe system in place ... <thinking>.

Rik · Nov 07, 2010, 15:08:10

BT and failsafe in one sentence, James?

You don't stand a chance against them, my friend, as they have recently and spectacularly demonstrated to Scotland and Northern Ireland.

JamesAllen · Nov 07, 2010, 15:19:42

Quote from: Rik on Nov 07, 2010, 15:08:10
BT and failsafe in one sentence, James? You don't stand a chance against them, my friend, as they have recently and spectacularly demonstrated to Scotland and Northern Ireland.

LMAO.. Ah I'd never attempt to try and win against the fail whale that is BT..

However, a monitor script which auto reboots my router upon the default gateway being down could be a nice thing to have in place. I could then log when it happens as well..

Just hope this is a BT issue and not something with my kit etc.

Rik · Nov 07, 2010, 15:26:59

Have you got a spare router you could try?

JamesAllen · Nov 07, 2010, 15:33:34

Quote from: Rik on Nov 07, 2010, 15:26:59
Have you got a spare router you could try?

I have but it's a Zoom X6 which is ADSL 2 compatible I think but not recommended. Have to see if this happens again in the next 24 hours.

It's strange that sync is maintained and there are no errors shown in the router logs. It's like it just suddenly loses it's route to the gateway. The IT geek in me wants to be able to do more low level debugging.

Rik · Nov 07, 2010, 15:38:02

Loss of PPP is a typical symptom of BT doing 21CN upgrade work. It may not be the case for you, but it is very common.

zappaDPJ · Nov 07, 2010, 20:28:04

Quote from: Technical Ben on Nov 07, 2010, 13:26:32
Is that with multiple DNS settings (IDNet versus Open DNS for example?).

I have IDNet DNS settings hard coded into my network settings. It's the only way I can connect.

The Thinkbroadband Ping Monitor still sees my modem. It records the event showing a huge increase in ping and a packet loss spike.

JamesAllen · Nov 10, 2010, 19:18:14

I've just had another of these connection failures - where the router stays synced but can't get to the default gateway.

To fix I just had to go into the basic settings panel on the Netgear D834Gv4 and click 'apply'. This renegotiated the connection and it started working again - no reboot required.

This is quite concerning as I can't afford to lose my Internet connection randomly like this, especially when broadcasting.

When searching I saw mention of some people having this exact issue with Netgears on their O2 connection. O2 apparently said they were working on a fix for it.

It's just finding out where the issue is here. Probably not related but my sync is the highest it's ever been at the moment:

ADSL Link
Connection Speed
Line Attenuation
Noise Margin

Downstream
15755 kbps
25.0 db
3.0 db

Upstream
1132 kbps
11 db
5.8 db

Although I've noticed that pings seem worse than when I first had the connection activated.

idnet.co.uk - 30ms

I'm sure it was 19ms when I first had the connection turned on.. hmmm.

Steve · Nov 10, 2010, 20:56:21

Downstream Noise margin is set at the minimum for adsl2+, might be worth running routerstats to see what's going on.

JamesAllen · Nov 10, 2010, 22:49:48

Quote from: Steve on Nov 10, 2010, 20:56:21
Downstream Noise margin is set at the minimum for adsl2+, might be worth running routerstats to see what's going on.

Hi Steve,

What should I be looking for with Routerstats? It just monitors the values that the Netgear control panel reports doesn't it?

The noise margin has dropped to 2.9db now.

Is this something I should be concerned about?

Steve · Nov 10, 2010, 22:59:04

Routerstats just keeps a time related plot of the margin , I was wondering if it was dropping to 0 at any time.

I think it most likely makes more sense that your margin must be fairly stable otherwise the MSAN wouldn't let you run on 3.

JamesAllen · Nov 10, 2010, 23:03:02

Quote from: Steve on Nov 10, 2010, 22:59:04
Routerstats just keeps a time related plot of the margin , I was wondering if it was dropping to 0 at any time.

I think it most likely makes more sense that your margin must be fairly stable otherwise the MSAN wouldn't let you run on 3.

Thanks Steve - I appreciate your help on this. I'll keep router stats running and see if it sheds any more light.

The problem I'm seeing sounds quite similar to one o2 / be users have faced where routing is suddenly lost but sync is not. There is a technical fix I could apply to my router to test this out. Of course this may not be related at all but it may be worth a test at least:

http://forums.thinkbroadband.com/o2/3669186-anyone-regularly-losing-routing-2.html?fpart=16

JamesAllen · Nov 11, 2010, 19:12:09

An update regarding the noise margin. I have been running router stats and the noise margin stayed around 6db for most of the day then at about 15:20 ish is dropped right down to about 3.2db. It's been steady since then and is currently at 3.4db.

Not sure what this is saying but thought I'd update you. No routing losses since the last time.

I am tempted to flash the latest DGTeam firmware onto my router to see if that helps.

Rik · Nov 11, 2010, 19:13:09

It's saying that, as it gets dark, your NM drops, James. That's normal, mine's currently at 5.1 from 6.6.

JamesAllen · Nov 11, 2010, 19:15:33

Quote from: Rik on Nov 11, 2010, 19:13:09
It's saying that, as it gets dark, your NM drops, James. That's normal, mine's currently at 5.1 from 6.6.

Does seem quite consistent in that it drops each late afternoon. All good then.

It does look like the issue may be with my router.

Rik · Nov 11, 2010, 19:17:35

Could be, but that drop in NM isn't a sign of any fault, James, just the extra electrical noise that starts as darkness approaches. Wait till Xmas, we're almost certain to get someone being affected by fairy lights.

JamesAllen · Nov 11, 2010, 19:20:11

Quote from: Rik on Nov 11, 2010, 19:17:35
Could be, but that drop in NM isn't a sign of any fault, James, just the extra electrical noise that starts as darkness approaches. Wait till Xmas, we're almost certain to get someone being affected by fairy lights.

Thanks Rik. I didn't necessarily think it was but I was asked to monitor this via routerstats to see what was perhaps going on.

Isn't a drop in a noise margin a good thing though which allows a higher sync or is it the other way around?

Steve · Nov 11, 2010, 19:21:56

Has your sync rate dropped recently? You seem to have a margin of 6 currently .I wonder yesterday whether it was set at 3 and the MSAN has decided it was too low and upped it to 6.

I suppose it could have been 6 all along but a swing of 3db is not ideal