BT do a LOT of traffic management - fair enough on the one hand but... they throttle video traffic during peak times on all packages (not just 1 and 2 as they claim) often making it unuseable... depending a bit on demand and your exchange congestion... they seem to send out the 80gig warnings when you go over 50gig (combined up/down) but throttle you from that point NOT the point where you go over 100gig 
there seems to be a lot of inconsistancy as well over the unlimited package useage warning:
For august I got sent a "80gig" warning sometime late on the 27th - by the router I'd only used 60gig - being that the monday was a bank holiday the rest of the family went away for a long weekend and all PCs but mine were switched off until tuesday (1st sept.) by my own calculations I used less than 5gig over the entire weekend - on tuesady I got an email stating I'd used 100gig in August...
For sept. I got an email on the 15th claiming I'd gone over 80gig (approx 50gig by my calculations) so we basically just piled on the downloading - pretty sure we managed 300gig by the end of sept... absolutely no 100gig warning... tho throttling at peak times has been in affect since the 14th.
there seems to be a lot of inconsistancy as well over the unlimited package useage warning:For august I got sent a "80gig" warning sometime late on the 27th - by the router I'd only used 60gig - being that the monday was a bank holiday the rest of the family went away for a long weekend and all PCs but mine were switched off until tuesday (1st sept.) by my own calculations I used less than 5gig over the entire weekend - on tuesady I got an email stating I'd used 100gig in August...
For sept. I got an email on the 15th claiming I'd gone over 80gig (approx 50gig by my calculations) so we basically just piled on the downloading - pretty sure we managed 300gig by the end of sept... absolutely no 100gig warning... tho throttling at peak times has been in affect since the 14th.