Tag Archives: ADSL

Communication Difficulties

Apologies if you’re trying to get in contact via e-mail with either myself or Beth over the next few days. Since Monday night our previously pretty well rock solid ADSL connection hasn’t been able to maintain a connection for more than about a minute before losing synchronisation and reconnecting, as a result doing pretty much anything on the internet is a bit of a pain at the moment.

Zen, our ISP were pretty helpful, and on my first serious use of their technical support since moving to them five years ago I was very impressed. Rather than the expected series of “have you plugged it in?” type questions, the engineer immediately gave me the information I needed to know, which was details of what their system at the other end of the line was saying about the connection. There was also no argument about performing an additional series of line checks. Unfortunately those showed up no problems with the line, so I was advised to do a more detailed series of checks on the router and the connection.

Router wise I’m running the latest firmware, and even after a factory reset it is still failing to hold a connection for much more than a minute. From there I’ve tried it in an alternative phone socket, and tried disconnecting some of the other devices. One suggestion is to try an alternative router, so after the discussions about issues with AR7 chipset routers, of which mine is one (see this PC Pro article), I’ve ordered one of the non-AR7 chipset routers that Zen recommend.

Unfortunately if that doesn’t solve the problem then I’m going to need to get to our BT master socket, which is hidden away behind our sideboard, as often BT will only look at the line once all other possible sources of interference have been excluded. They do that by having you plug the router directly into the test socket located behind the master socket faceplate. In this way they can exclude any extension wiring issues from the problem.

As with most problems like this, with a multitude of things that could go wrong, and several different organisations responsible for different parts of the connection, trying to nail down exactly what changed on Monday night to cause our connection problems really does end up being a pretty tedious process.

Update: Hooking the router up to the test socket produced exactly the same problem, so on the phone to Zen we went through the connection statistics the router was reporting and compared them to what they were seeing – the stand out oddity was the SNR figures – signal to noise ratio – which were radically different at our end from what Zen were seeing. We were getting 6/22, they were reporting 22/365! This was enough to be able to report the problem to BT, who picked up the problem this morning.

BT spent all of twenty minutes on the problem, and basically turned on interleaving. What this did was sort out the problem when the router was plugged into the test socket – their yardstick for a working line, but the router was still unusable when plugged into the master socket. Unfortunately, BT were going to do no more, so I resigned myself to having to rearrange the wiring in the house to filter the ADSL signal at the test socket. But then when I got home, looking at the router logs it had dropped and reconnected about fifteen minutes before I got home. The speed was a lot less – about half of what I would usually expect, but the SNR had changed to 9/22. I tried the router plugged into the master socket and it worked, then I moved the router back to the original location on the end of an extension, and again it worked. Indeed there is nothing different in the setup now than with the way it was on Monday before it failed. Fingers crossed there was some sort of external interference which has now gone, and hopefully we won’t get any more problems.

One final note, this is the first time I’ve had to make serious recourse to Zen technical support, and without fail, all the engineers I have spoken to have been helpful and knowledgeable, and at no time have I felt that I’m fighting them to get what I need to solve the problem. A totally different experience from what other people seem to find with their ISP customer support.