Low download speed...

[#1]

Thanks Matt,
Right, my broadband is now healthier than it has ever been, but I'm still in the test socket so now I need to start troubleshooting my phone extensions. Assuming there is a fault somewhere, I'm going to have to reconnect several times at a variety of speeds. Is there a way I can do this so that BT don't automatically bust me back down to a couple of Mbps?

[#2]

This is the safest guide

Quote from: Anotherone

Log in to the Modem/Router, in the Internet box, click Disconnect to drop the PPP Internet session (this is not the sync), wait about a minute and then power down the Modem/Router. After about another minute you can unplug it from the line. Do whatever is needed, but stay offline for at least 10 minutes. When you re-connect and power up, Login to the Modem/Router and click Connect to establish a new PPP session. Don't do this more than 5 times in an hour, then leave it for the rest of the day. This method is to help stop the Exchange DLM from thinking your sync loss was a dropped connection.

[#3]

Awesome. Thanks for that. I'll get diagnosing this weekend.
My broadband was flying last night. 5.5Mbps is a lot out here in the sticks!

[#4]

OK, here's the results from reconnecting all my phone extensions and removing one device at a  time. I have five phone sockets, three of which have devices pluged into them. Each device has a microfilter. The sockets which do not have devices atached do not have microfilters.
With all devices attached my speed dropped to 3Mbps.
With the phone only removed the speed dropped even further (2Mbps).
With the Sky box only removed the speed went back pu to 4Mbps.
With just the fax unplugged the speed dropped again to 3Mbps.
Going back to the master socket the speed was back up to 4.37 but by this time BT had busted me back down to an IP profile of 4.5 so I'll assume I would normally be back up to full speed.
I will wait for my IP profile to come back up to full speed again and then repeat these tests by just attacing one device at a time.
Any ideas in the meantime?

[#5]

Well, looks like your sky box is having the most impact on sync speed, followed by the fax. On the plus side your phone seems not to make much of a difference.

[#6]

I suggest tackling this in a different way and there's no need to wait for the IP Profile to increase.
You currently know the sync speed when plugged into the test socket. If you disconnect all devices, put the face plate back and plug the router into the normal socket via a filter do you still get the same sync speed (and noise margin)?
Assuming (nominally) yes; don't bother doing a speed test, plug in the phone and record the noise margin. Hopefully minimal effect. Lift the handset and check again. Still the same? Next plug in the fax and record the noise margin again. Is the change significant? Finally plug in the Sky box. I expect that *will* have a significant effect. If you change its filter is the effect the same? If you double-filter it is it the same? Can you plug it into a different socket - still the same?
It's possible plugging the Sky box in might cause your connection to drop. In this case record the noise margin with and without the Sky box plugged in (without re-syncing). The noise margin should increase when the Sky box is unplugged. For a complete picture you could check noise margins with and without other devices at this lower sync speed.
Hopefully this will show the Sky box is the culprit for your poor speeds.

[#7]

Well this was a bit of a surprise.
When I connect only one device at a time, or even just go back to the normal socket with no devices connected, the speeds and stats are very similar. Connecting the Sky box did cause the connection to drop and re-sync at a lower speed, but the actual speed test result was only slightly slower then with just the fax or phone connected.
However, when I connected the fax and the phone I got the same speed as I dod for the same combination on the 17th August.
I have left my fax and phone plugged in to see if the conection remains stable, plus I am getting tired of people saying they can't contact me at home I'm planning on binning Sky anyway, but I'd really like to get to the bottom of why my phone extensions are robbing me of a whole Mbps or more.