Will a long DSL wire hamper download speeds or latency?

[Zebedi1]

So as we live in an old Victorian house, the walls are solid and VERY thick so you can imagine getting wifi to all corners of the house isn't easy. We all have powerline ethernet to our computers and TVs and we have two WIFI extenders at different places in the house. The problem is that the telephone line comes into the house in not so much of a convenient spot. The repeaters are only just able to reach a signal from the router as it is in a corner of the house.

I have run a 10m DSL cable from the master socket to a more central location in the house. Will having a long cable make speeds suffer over time? I have no idea how old the cable is or hte quality of the cable as I got it off a friend who found it in his electrical box.

With Sky Fibre, we should be getting speeds of about 36Mbps, using powerline I am able to get speeds of 36.95Mbs and on Wifi about 5-20Mbps. I have taken a snip of my noise margin, line attenuation and connection speed but I don't know how to interpret these numbers? https://imgur.com/a/Y1TWrjp

Thanks.

 

[camieabz]

Assuming the ends of the cable have been wired and terminated properly, anything up to 300 feet (91 meters) should be fine. Running the cable past power sources, and areas of interference might degrade an unshielded signal a little, but less likely.

Connection speed (39999 / 10000) - This is your download and upload connection speed, i.e. the maximum speed your line will receive if everything is peachy. It's a contracted speed, as opposed to a maximum line speed, and is set by Sky. This isn't your throughput speed (the actual speed you can get, after line overheads have been applied).

Line Attenuation (12.8dB / 0.0dB) - This is the 'resistance' on the line (down and up), and can be a gauge of distance to the exchange / cab. More line length = more resistance = higher attenuation = less speed. Your connection above has already established that this isn't an issue.

Noise Margin (17.3dB / 24.24dB) - These values are set in part by the quality of the connection, and in part by the auto-sensing equipment from the wholesale provider (presumably BT). Dynamic line management (DLM) will test the line over the initial line training period to ascertain line quality and speed, and set the noise margin accordingly to ensure maximum uptime and best speed within that.

Your noise margin values are generally supposed to be 6dB on the download (the upload value escapes me), and higher numbers will cause lower speeds. Now you have to work out why your noise margin is so high.

One thing before you start testing. Every router/modem reboot sends a flag to the DLM. Several of these, and the DLM will trigger a noise margin increase as it assumes that the line is unstable, and increases the noise margin to ensure a stable line (which is a slower line). Ergo, line testing via reboots invalidates line testing. Gotta love UK broadband.

The best solution is to get a very short, reliable cable and connect your router/modem to the master faceplate directly. This all but removes internal factors. Once setup there, leave it well alone for 7-10 days (no really). If there noise margin hasn't reduced / speed increased, then you'll have to go down the road of asking your ISP for a DLM reset, and let them know about the noise margin values. Not all ISPs like having to do that, but that's something that should be done first. Don't be fobbed off. You can't contact the wholesale BB provider.

I do suggest that beyond this, you try posting your woes on the Thinkbroadband Forum. Some of the more knowledgeable folk there really know their UK BB onions, and the procedures for dealing with ISP vs wholesale issues.

 

[Zebedi1]

Thanks so much for your detailed reply, I only ask this as I want to secure the DSL cable to the wall and I need to ensure that this setup works. Will try the tests you recommended.