Frustrating speed Dips

[Jaheira]

I've been with Sky Broadband Unlimited for over 4 years. All my devices connect to a Sagem F@ST 802.11g router using wifi (will they ever send me out a new n router!?!?).

For almost all of that time, my connection speed according to Speedtest.net has been about 8Mbps download and about 0.75Mbps upload, with the actual downstream connection speed in the router configuration statistics being about 1Mbps faster, I assume due to overheads associated with wireless. Here's a screenshot of typical router statistics when all was well:-

Attachment 4283

Over the past year I've experienced several dips in speed. Last May, my download speed dropped to about 5Mbps for about a 3 week period. Even after rebooting the router several times, the speed stubbornly remained the same (I was actually confined to bed at the time due to breaking both my legs, so in no position to try and sort out the issue!). Miraculously, 3 weeks later the download speed not only recovered, but went up to about 9Mbps, the fastest it's ever been. It then stayed there until January of this year, when it again dipped to about 6Mbps for a 2 week period. After that dip, it then recovered to about 8Mbps until about early March. Initially, it dipped to about 5Mbps, but is now at 4.3Mbps, about half the speed I'm used to! During that roller coaster ride, nothing has changed on the line. The connected devices are exactly the same, nothing has been added or removed and rebooting has made no difference. When speed has recovered, it has done so with no physical changes made whatsoever. All the download speeds I quote are over wifi and therefore around 1000kbps slower than the actual router downstream connection speed (as I described earlier).

Here's a screenshot of my router stats at the moment, with my wifi download speed of about 4.3Mbps:-


My Line Attenuation is about the same as in the first image (when speeds were much higher), and the Noise Margin actually higher (therefore better), yet the router is connecting 4000kbps slower! And, weirdly, every time I reboot the router the downstream connection speed is ALWAYS 5022kbps. Whenever I rebooted before, the dcs always varied each reboot by about 200kbps. Now it's always 5022kbps. This implies to me that Sky are somehow capping my speed so that this is the maximum I can connect at even though my line is obviously capable of considerably higher speed.

It's really doing my head in now because I've been experiencing slow speeds for almost 2 months without recovery. Anyone have an suggestions to resolve this issue? Are my suspicions about some form of speed capping justified? Thanks in advance for any help/suggestions/input!

[Isitme]

It looks like DLM has found a problem with your line and capped the speed at 5024mbps/800mbps. Plug into your Test socket and see if there is any change in the noise margin. If it goes up it means something internally is causing interference, you should fit and use a filtered faceplate. If it remains the same or only rises slightly, call Sky and ask them to rerun DLM training on your line as it has left it below its full potential.

[Jaheira]

I tried the line with only the router connected, and exactly the same speed (5022kbps). I don't have any extension lines, just a master socket in my lounge. I'll give the test socket a whirl later.

What I can't understand is why there have been speed dips before, and yet the line has then recovered without any intervention on my part? As I said, the first time this happened I was laid up in bed. If it hadn't been for me being unable to sort anything out, then I'd have been pulling out leads/changing microfilters/phoning Sky. Yet the line speed recovered on its own 3 weeks later going from 5Mbs to 9Mbs.........

[Isitme]

I tried the line with only the router connected, and exactly the same speed (5022kbps)

As I said already, your speed is capped so you will not see an increase in speed, what you may see is an increase in the noise margin, that is what we are interested in.

[Jaheira]

Righto!

When I came online this evening, I noticed my download speed appeared even more sluggish (I can tell from the time I takes to download definitions for SuperAntiSpyware and Malwarebytes!!). Here are my router new (even slower) router stats:-



I did as you said and removed the faceplate and plugged the microfilter into the master socket and connected only the router. The line stats are almost identical:-



When I took off the faceplate, it came away completely as there were no wired extensions to that line. So, does this firmly place the problem at Sky's end? The only thing I haven't been able to do is try a different microfilter, as the person who actually pays for the service has managed to lose the other one Sky sent us!

[Isitme]

When I took off the faceplate, it came away completely as there were no wired extensions to that line.

Is there only one phone socket in the house? If there is not, there will be no wires attached to the faceplate. If there are other phone sockets, then the wiring is incorrect and could account for your problem.

Assuming there is only one phone socket, you should call Sky and ask them to reconfigure your line as DLM has left it with a low speed.

[mattan]

May also be worth checking with a different microfilter?

[Jaheira]

Yep, it's the only socket in the house. There's actually another master socket upstairs which had a second line for dial-up, but that was disconnected years ago.

I was pretty sure all along that the problem was at Sky's end, since the speed dips I've experienced before (as I described in my opening post) resolved with no intervention on my part. Could the fact that I've rebooted the router about 15 times in the past few weeks to try and resolve my current situation be exacerbating the problem by making the DLM think the connection is dropping? As for this whole DLM issue, it appears to me to be a monumental pain considering the speed issues it's given me. How many other less computer savvy people have speeds way below what they should be getting without realising? As I speak, my download speed according to speedtest is about 3.5Mb/s when it was completely stable at about 9Mb/s for most of last year.

Also, what personal details are Sky likely to ask me when I phone them? I'm not the person who pays the bill, and since that person would have little idea how to describe the problem (a computer illiterate family member!) it'd be much easier if I pretend to be that person to best sort out this issue!

May also be worth checking with a different microfilter?

If the microfilter was dodgy, wouldn't my line attenuation and noise margin figures degrade? Since they are the same now with a download speed of 3.5Mb/s as they were when I was getting almost 9Mb/s, doesn't that imply a DLM issue at Sky's end?

[jayhab]

You mention a 2nd master socket, is / was it physically a second line, or was it installed using the 'spare' wires from your main phoneline?

[Isitme]

Also, what personal details are Sky likely to ask me when I phone them?

You may be asked for the account password and probably your post code and the answer to a secret question. It would be better if you have the account holder handy to make the call, then pass it over to you.