Cachelogic put appliances into the network that both monitor traffic
(semi-deep packet inspection) and also cache P2P content to take the load of
your network. While I don't think they made the figures up it's worth
bearing in mind they are selling a 'solution' to the problem they highlight.
For the record we have seen P2P traffic over 50% of our bandwidth
utilisation - if bittorrent is the largest proportion then it could reach
35% of total bandwidth.
Matt.