Bad connection

dunkers · Mar 01, 2008, 01:39:58

Is there something up this evening? I've had to switch to my Entanet connection in order to post this

There are two problems I seem to be having: firstly tracerts would fail in interesting ways to various places, and trying to post messages on a BBS, for instance, would sometime be fine and other times very very slow. Some sites I can reach whereas others, at the same time, I couldn't.

Secondly, my connection seems to be down quite regularly for up to a minute at a time. You can see from this chart that my normal 10-15ms pings have taken a strange dive today. The packet loss bars are misleading - sampling is happening at 5 minute intervals here, so I could lose the connection and so long as it's back before the next sample it won't show up.

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Sebby · Mar 01, 2008, 01:42:26

You mention an Entanet connection; that means you have another line for that service? Two lines can be completely different. Could you provide a bit more information about your setup on the IDNet line, and also post your router stats?

dunkers · Mar 01, 2008, 01:59:20

Wow! You replied there before I'd finished posting

Router stats could be tricky you want anything deep - it's an Edimax AR-7084A and the webificated interface has:

Code Select


		 Downstream 	 Upstream 	 
       SNR Margin:	5.5 	9.0 	db
 Line Attenuation:	46.0 	31.5 	db
        Data Rate:	6144 	832 	kbps

The IDNet line used to be Nildram and had few problems (other than Pipex and then Tiscali taking over). It used to run a Vigor 2600 and stayed up for months at a time, although this was with a fixed 2MB service. When I changed to IDNet about 4 weeks ago I left the Vigor as it was. On migration, I gaine interleave which I asked support to remove, which they did. All seemed OK except that there would be strange pauses periodically, and I put this down to the Vigor running out of steam on a MAX line, hence the swap to the Edimax.

I had this sort of trouble a week or two back and then it cleared up for a week and I got an uptime of 5+ days.

Sebby · Mar 01, 2008, 02:06:12

Okay, the stats look good. You've got a very decent sync for a 46dB line. The SNRM is healthy too, so there's no issues in this department.

Does the Edimax provide any log of errors? I wonder if your line could be suffering from high errors now than interleaving has been turned off.

You could do a BT speed test too and post the results. It's always useful for us to see, though perhaps not so much in this case.

Do you have a NTE5 master socket? If so, could you remove the front plate and connect the router to the socket behind (the test socket). Then see if things are any better in terms of pings and pages loading. Again, I don't think this applies so much in this case as your stats look fine, but it's always good to check.

Lastly, it might be worth changing the microfilter/RJ11 lead if you haven't already. I'm sure it's not that, but it's good to eliminate everything if possible.

If none of the above makes any difference, I think it might be one for IDNet, who'll perhaps have to raise it with BT.

dunkers · Mar 01, 2008, 02:26:32

The log is typically along the lines of:

Code Select


1/1/2000 6:0:27> MPOA Link Down
1/1/2000 6:0:27> SNMP TRAP 2: link down
1/1/2000 6:0:43> netMakeChannDial: err=-3001 rn_p=804649f8
1/1/2000 6:0:51> Last errorlog repeat 1 Times
1/1/2000 6:0:51> MPOA Link Up
1/1/2000 6:1:16> ppp_ready: ch:804764d0, iface:803f9090
1/1/2000 6:1:16> SNMP TRAP 3: link up
1/1/2000 6:1:16> Accept() fail
1/1/2000 6:1:16> Accept() fail
1/1/2000 6:7:50> MPOA Link Down
1/1/2000 6:7:50> SNMP TRAP 2: link down
1/1/2000 6:8:14> MPOA Link Up
1/1/2000 6:8:40> ppp_ready: ch:804764d0, iface:803f9090
1/1/2000 6:8:40> SNMP TRAP 3: link up
1/1/2000 6:8:40> Accept() fail
1/1/2000 6:8:40> Accept() fail

The date I forgot to set after resetting the router earlier to see if that would fix things.

The speed test nearly always comes out great. I had it very low once, but every other time it's impressive and implies the full line ability is utilised.

The master socket isn't like that one, but has separate sockets for phone and modem. I'll whip out the phone and see if that helps any. Thanks for your help/interest

Mytheroo · Mar 01, 2008, 03:34:01

5.5db snr downstream is right on the cusp, if you have some extra noise at points this will cause the loss of sync. Have been doing alot of testing with my parents and it was dropping all the time with 5-6db. (6km line 61db att.)

See if you can get it changed to 9db snr. Is it connecting with a.gmt or ADSL2 do you know?

paulsmith109 · Mar 01, 2008, 07:03:27

I `ve also seen ping variations on my connection. By disconnecting and then reconnecting PPP (no loss of synch) I can regain a steady ping of 11-12ms. Do you connect via the `gw5` realm by any chance?

J!ll · Mar 01, 2008, 08:42:30

dunkers

Ray · Mar 01, 2008, 10:00:05

Dunkers

and have a welcome

Rik · Mar 01, 2008, 10:11:45

Hi Dunkers and welcome to the forum.

I also had to dump a 2600 on moving to Max, it just didn't seem to be able to cope. Sebby has taken you through everything I would normally suggest, I just wonder if it's possible for you to extract the error count from the router? Usually, if interleaving gets turned on, it's for a reason, and it may be that you're getting bursts of noise, and with it errors, which is causing the problems you are seeing.

If you're satisfied you've eliminated your own equipment and wiring, give support a call and they can test the line and, if necessary, get an engineer out to you. Be aware, though, that if he/she finds the fault on your side of the master socket, they will raise a charge of £160+.

Simon · Mar 01, 2008, 12:07:08

Hi Dunkers, and

dunkers · Mar 01, 2008, 14:39:25

Thanks for the welcome, people 8)

@Mytheroo: On checking this ~~morning~~afternoon the SNR is reported as 8.5 down and 9 up, with basically the same attenuation. I wonder if that's because I unplugged the phones last night... For connection, all it says is g.dmt on the webcon front end.

@paulsmith109: Yep, it's the gw5 realm. I'm hesitant to ask if that's good or bad

. I did try a router restart when there were obvious problems, and that didn't affect anything that I could see.

@Rik: The ADSL error count on the router stays at 0 whatever seems to be happening. It doesn't inspire confidence in the report, though - the Vigor would show corrected and uncorrected errors, as you know. <pokes around a bit...> Ah! I get this from the telnet interface:

Code Select

near-end FEC error fast: 0
near-end FEC error interleaved: 0
near-end CRC error fast: 972
near-end CRC error interleaved: 0
near-end HEC error fast: 1424
near-end HEC error interleaved: 0
far-end FEC error fast: 0
far-end FEC error interleaved: 0
far-end CRC error fast: 12
far-end CRC error interleaved: 0
far-end HEC error fast: 6
far-end HEC error interleaved: 0
Error second in 15min           : 2
Error second in 24hr            : 429
Error second after power-up     : 429
ADSL uptime     7:50:31

Means nowt to me, and I think the line is OK at the moment anyway.

Something I haven't mentioned is that I get a similar problem on the Enta line. I didn't mention it before because that do it at different times (that is, one will be fine and t'other a bit dodgy), and the IDNet line has only started doing it since I dropped Nildram. Er... and it just occurred to me that Nildram wasn't MAX. Doh!

So... given that, does it sound like a problem between the pole and premises? BT have checked the Enta line and found nowt wrong from the exchange, and want the £160 to come out and poke around here. However, a client also on Enta had dropping connections and got the full BT call out thing but they reported no fault and they just basically put up with the drops. A month or so ago they lost the line completely for 6 days and BT eventually found a problem with the incoming pairs (there was another problem as well, but that's something else). The pairs were fixed and the connection has been up ever since. The point I'm getting to here is that I could easily see BT coming out and finding nothing wrong but stiffing me for the £160 (or £320!) all the same.

Rik · Mar 01, 2008, 14:54:15

Your error count is quite low, and interleaving is not on, so the line looks fundamentally sound. If the Enta line is doing something similar, it would suggest an external noise source or a line fault - the problem is going to be finding out which it is from your side of the connection. I'd suggest contacting support, letting them know what is happening and that it affects the other line too. They can they test and see what's visible to them. Possibly, if you report your Enta line too, the response from them will enable a sort of 'triangulation' to try and determine what is happening. Ultimately, though, you do risk being stuck with a hefty bill - not an ideal situation.

I do know that IDNet will try to ensure that doesn't happen by eliminating your side of the master socket as far as possible.

dunkers · Mar 01, 2008, 15:43:05

Yes, I think that's going to be inevitable now. My reason for posting originally was mostly to check that it really is a problem here (i.e. that no-one else is suffering, as happened a couple of weeks ago). I'd really hate to spend an evening swapping kit out if unnecessarily

. Your diagnosis is much appreciated

Rik · Mar 01, 2008, 15:49:08

Have you tried wandering around with a de-tuned MW radio, btw. Follow the path of the phone line and see if the noise increases anywhere.

dunkers · Mar 01, 2008, 17:40:20

That's clever idea! I can't at the moment 'cos I'm deaf and my partner is AWOL at the moment, but I'll get her to try it when she gets back.

Rik · Mar 01, 2008, 17:47:51

Sorry to hear about that, Dunkers, it must make life difficult for you at times.

ADSL operates in the MW band, so if the radio picks up noise, your ADSL will be doing too. Take the radio off tune, to an area of the dial between stations, then it will latch onto any signal in the spectrum.

Sebby · Mar 01, 2008, 17:52:06

For a 46dB line with interleaving off, the line looks to be great, so I'm at a bit of loss. Rik's suggestion of a detuned MW radio is the best way of finding a noise source, though I must admit that I'd be surprised if there was a source of noise around as the sync is so good for a 46dB line!

Rik · Mar 01, 2008, 18:13:54

Me too, Sebby, but it's worth a try.

Sebby · Mar 01, 2008, 18:34:10

Indeed. Anything's worth a try in these mind-boggling cases!

Rik · Mar 01, 2008, 18:51:19

It really comes down to try everything you can to prevent BT raising a no fault charge. After which, offering a sacrifice to the gods of ADSL sometimes works.

dunkers · Mar 01, 2008, 21:20:50

It's back to very bad again tonight, and I noticed that the SNR was 4.5 (now at 5.5). How would I go about getting it pinned at 9? Just talk to support?

Gary · Mar 01, 2008, 22:06:14

The snr is not hugely bad for this time of night, each 3db increase reduces your overall speed as far as I am aware, I have connected at 3db at night with my old router and not had any speed of throughput issues though $:-\$

dunkers · Mar 01, 2008, 22:17:58

Oh well. Seemed a reasonable straw to clutch at the time

Sebby · Mar 01, 2008, 23:39:16

4.5dB isn't bad for night, as Gary says. If you sync during the day at 6dB (the default target) then it's going to decline at night. If you sync at night, you'll have a SNRM of 6dB at night and higher in the day.

But, like I say, your stats really do appear to be fine. You could get your target SNRM upped to 9dB, but I don't think it'll help, unless of course we find out the issue is errors (thought we've seen that your error count is quite low, unless your router is reporting inaccurately).