BT has been accused of slowing down its internet connection in the evenings when users try to watch or downalod TV programmes using the BBC iPlayer.
The BBC has spoken to a viewer who complained that his internet access bandwidth speed dropped to 2Mbps after 5pm.
This is not the first time BT has come under pressure for throttling bandwidth. Users of peer-to-peer download sites have previously complained on bulletin boards that the network bandwidth they get from BT is far less than it should be.
Streaming multimedia applications like the iPlayer, YouTube and music download sites like Apple's iTunes and Amazon are increasing the pressure on internet bandwidth. According to a dblog produced by ISP PlusNet,
"One thing we have noticed is that the mean usage is on the way up and in particular the type of usage is streaming and it is being used more in an evening."
ISPs often use packet shaping appliances to optimise network traffic.