Tuesday, March 8, 2011
Managing upstream traffic was always an important goal and challenge for ISPs, and in many access technologies the upstream channel has limited capacity, and some applications (such as P2P file sharing) might cause congestion and effect also time-sensitive applications (even if those are basically "downstream" applications, such as video streaming). In addition, is the upstream traffic goes to off-net users, it may impose additional costs to the ISP.
See the post by Mark Wilkin - "Upstream P2P Traffic Management Peak Time Trial - 2nd March" - here.
Virgin's traffic management policy is explained here, and summarized in the chart below (which does not match the above message so well).