There has to be something to this, other than Paranoia (As BT would have us beleive). Please bare with me while I outline my experiences -
I have been on 8MB ADSL Max for a year and have always had good speeds until a month or two back. My sync rate has never fallen below 8128/448 that I have witnessed, yet my service is at a crawl now in comparrison. Downloads from the premium UK servers on 3DGamers.com used to give me download speeds of anything between 450KBs - 750KBs at anytime of the day, now I cant seem to get above 50KBs - 70KBs. The slowdown is across the board, for browsing, downloading, streaming, everything in fact, apart from one thing.
I had BT Vision installed last week and when the engineer asked me to do a speedtest (
www.speedtest.net), I got 1945 down and about 380 up. I said that I had noticed that everything was much slower recently and he told me that with that speed, I may not be able to get the VOD service, although when it came to it, it runs fine. I then started to look into it a bit further and ran the BT speedtest and this showed me with a profile of 2000Kbs. This seems strange as I was certainly getting a hell of a lot more than that before. Here are my sync speed, SNR readings etc
Data rate (Kbps) 8128 448
Noise margin (dB) 16.4 24.0
Output power (dBm) 19.8 11.9
Attenuation (dB) 21.0 12.0
I rebooted the router and when I ran the speed test a little later, it was showing me a profile of 500Kb. Now from reading this thread, I know that the profile will take time to come back up to the sync speed. I thought I would try an experiment while the various speedtesters were telling me that my connection was 500Kbs. What I did was start off a download from 3DGamers, which very soon leveled out at 50KBs, then I started watching an episode of Band of Brothers on BT Visions Video On Demand service. The download speed from 3DGamers did not change drastically, it may have slowed by a couple of KBs. Now it has been explained to me that the VOD service requires an absolute minimum of 1.6mbs available bandwidth to run, which it then reserves for the stream.
How, if my IP profile was 500kbs (according to various broadband speed testers) and I could only get 50KBs from a certified premium download server, could I be getting a 1.6mbs connection for the VOD, unless there is some serious traffic shaping going on, including HTTP traffic. And why I am I suddenly unable to get an IP profile above 2mbs, when the equipment is all the same and plugged into the same socked (a filtered socket installed by a BT engineer).
Surely BT must be capping & shaping peoples ADSL, so they can guarantee bandwidth for BT Vision, I can think of no other reason why so many people are experiencing these problems.