Unusual problem at exchange or backhaul (?)

We have 2 ADSL lines to our offices on a small rural exchange WMSUC one with IDNet and one with Newnet.

During the past few weeks we have been experiencing the same intermittent problem on both lines, as have 2 other companies in the same business centre, the local post office and 3 local residents who were in the PO at the time of one visit.

When the problem occurs it can effect one or both lines, sometimes start times are simultaneous on both lines sometimes not. It usually lasts several hours to several days, then can be free of problems for a few days.

When the problem occurs:-

Both lines are in still in sync at about 8000kbps.

Browsing is impossibly slow approx 1 min to load www.idnet.co.uk or www.newnet.co.uk. www.bbc.co.uk usually times out.

Thinkbroadband speedtest fails with unexpected error during quick upload test

Speedtest.bt.com usually fails with IE cannot display page but on one occassion has completed with a satisfatorary download speed of 4055Kbps

FTP to our UK based website gives a dowload speed of around 500Kbytes/sec but any attempt to upload a 100KByte file continuously fails and retries until the 15min timeout occurs in Filezilla.

Thinkbroandband ping monitor shows significant packet loss.(Problem starts at 8pm on these snapshots)

http://www.thinkbroadband.com/ping/share/79fdf959414...

http://www.thinkbroadband.com/ping/share/4cfe272f1f2...

Incidentally Newnet support have been great, listened to my phone calls and read my emails and been very helpful, but clearly limited by BT.

But I am very disappointed with IDNet support, they are little or no better than an offshore call centre, appear to not read emails and just reply with the mantra "BT have checked and there is no fault on their side, it must be your line/equipment, the other 8 lines with the same problem is just a co-incidence."

Any thought on what might be wrong or how to get it fixed?

Tim.

Given that you have 2 separate lines experiencing the issues and have some anecdotal evidence of others experiencing similar/same then it's likely to be something at the exchange.

How does the main cable come into the area ?

As everything goes down then it could be cable related - but as the connection is still there albeit slow possibly noise.

I have seen one case where three properties were fed - 5 circuits on shared poles. One of those poles had an autoswitching transformer on it which fed a couple of properties. They would suffer from very slow connections including upstream for periods of 1 to 2 hours and it tended to be lunchtime and early evening. When their power failed the transformer was replaced and no problems since.

Can you trace the cabling back or is it underground?

Thanks for the reply.

Our cables to this single building business centre are underground. The post office is 1/4 mile nearer the exchange and one of the residents is 1/4 mile further away.

As there are times when one of our lines is fine and the other down I find it unlikely that it is interference.

I feel the reduction in ping time when the problem occurs also points to it not being interference related, I feel this might well be a clue to the knowledgeable about where the source of the problem might be.

The links in my original post appear dead here is another try.

My Broadband Ping IDNet

My Broadband Ping NewNet

Tim.

Hi Tim

I'm with IDNet and had a similar problem last month, lasting about two weeks. It affected both my lines, one 20CN, one 21CN, and was clearly noise in my case. Routerstats demonstrated the noise appearing on the line between 10-11am and disappearing some six hours later, both very abruptly, the graphs showed an instantaneous and simultaneous switch of noise margin. Whilst the 20CN line was relatively resilient (though with a massive amount of FEC errors), the 21CN line became very unstable. Both lines, for their different reasons, slowed to a crawl. The problem stopped as suddenly as it started, without intervention.

I'd been through the full range of diagnostics with IDNet, use of test socket, swapped filters and routers (3 in all), line monitoring on both lines, the MW radio walkabout etc. At the end they were faced with a choice of sending an engineer out, with the risk it was going to cost me, or accepting that, on a long line (62.8db attenuation), sometimes you just can't do much about it. This is really down to BT's attitude, which has taken many of the tests and management facilities away from ISPs in the past few months.

If packets are being corrupted, then ping time can increase, so it might prove helpful for you to run Routerstats on both lines and see if you see a similar pattern to the one I had.

My instinct, based on what I could see happening around here at the time, is that my problem was related to the extensive work which Openreach was doing. I'll never be able to prove it, of course, neither could an ISP.

I'd still be wondering if there were some REIN issue. Would be interesting to see some router stats for both lines, including error counts, at both 'good' and 'bad' times.

Thanks for your detailed reply.

I run routerstats on my home 50dB line but until now I have not on these 2 lines, but I have now set it up on both these lines.

One currently show an uptime 21Hrs with 9 downstream CRC 2 Upstream CRC. The other line shows uptime of 21hrs 1 downstream CRC 0 uptream. (we had problems until 3:00 yesterday).

IDnet line usually syncs at 8128 and 6-7dB. I manually checked these figures when we started having problems and they were normal. But I am not sure downstream figures are relevant as they problem only affect upstream. If speedtester.bt.com completes it gives a good > 4000kbps speed.on at least 3 affected lines.

I don't personally believe it is Interference as it can affect one line and not the other, I also can't see how it would reduce the ping time when there is a problem. IDNet are suggesting getting a REIN engineer out. I am happy to go along with this even if it means paying as it might eliminate one possibility.

Tim.
.

In reply to a post by TimJ:

I don't personally believe it is Interference as it can affect one line and not the other, I also can't see how it would reduce the ping time when there is a problem.

It could mean packets are being dropped and resent, Tim.

In reply to a post by rikbean:

In reply to a post by TimJ:

I don't personally believe it is Interference as it can affect one line and not the other, I also can't see how it would reduce the ping time when there is a problem.

It could mean packets are being dropped and resent, Tim.

The ping time reduces when the problem exists. Also ping does not resend packets, they are just logged as dropped packets.

I would agree that the very slow browsing is almost certainly due to dropped packets and resends.

Tim

Sorry, Tim, I'm so used to people reporting increased ping times I missed that and went into autopilot mode.