Traffic shaping

I'm reasonably pleased with the broadband service I get from BT (BT Vision is, unfortunately, another matter and there are still lots of problems to be ironed out) but it seems increasingly that BT are applying traffic shaping or capping during peak times.  A speed test a few minutes ago showed I was getting around 7.5 Mbs, which is close to the maximum on an 8Mb line. But earlier this evening, during BT's peak period of 6pm to Midnight the speed dropped to under 500Kbs, a drop of over 90%.  And this is happening every evening, although not always quite as severely.

Calling BT doesn't do much good. The response is always a standard list of 'things to do to speed your internet connection'. Everything from not putting your router on a carpeted floor to avoiding halogen lamps and cordless phones. But all of this is irrelevant if you get maximum speeds some of the time and piss-poor performance at peak times with everything exactly the same.

There is a way of checking whether your line speed is just slow or whether you are being capped. During a slow period download the following file (don't worry, you don't need to complete the download or open the file, which is completely harmless anyway).

Check the download speed in your download manager and then cancel the download. Now download the same file using FTP:

Again, check the speed. If there is a substantial difference between the files (that is, if the FTP file is downloading much faster than the HTTP one) then you know that you are being subjected to traffic shaping or capping by your ISP.

You can then confront your ISP and ask them to clarify their policy on shaping. Some ISPs make it clear that you cannot expect more than, say, 2Mb during peak times. If fast speeds in the evening are important to you then you might want to check what's on offer from other ISPs. 

As for me, it will be a phone call to BT technical first thing in the morning, even though I know I will have to listen to crap about my router's feng shui being all wrong or something similar.  But whatever they say I intend to get a better deal from 6pm to midnight than just a paltry 7% of what I'm paying for, take it from me.

UPDATE: I had a long chat with a guy at BT this morning and I was so impressed with the way he handled my enquiry that I spoke to his supervisor and got a promise from him that the guy would get a bottle of wine and some approbation from his superiors. Now, what was the chance of that happening?