EFF's staff technologists, Seth Schoen and Peter Eckersley, have been running experiments on Comcast's network. They've discovered that Comcast isn't just screwing around with BitTorrent packets, they're also jamming Gnutella and (according to another researcher) Lotus Notes packets. Lotus Notes! As in, corporate enterpriseware that suits use to synchronize their projects.
But when you try to run a Gnutella P2P node on your machine, things start getting strange. Gnutella operates in two stages: first of all, your node starts a conversation with other nodes on the network. Once that conversation is happening, nodes can say things to each other to organise searches for and downloads of files. We saw forged TCP reset packets that stop some of the nodes from being able to converse with each other in the first place…
It isn't just BitTorrent and Gnutella that are affected. Kevin Kanarski has reported that Lotus Notes (a suite of software that many businesses use for email, calendaring and file sharing) is also being interfered with. We haven't tested this ourselves yet, but Kanarski's packet traces look a lot like the ones we've collected with BitTorrent and Gnutella.
(via Isen)
See also:
Why Comcast's BitTorrent-fux0r is bad for quality of service
How the AP busted Comcast for blocking BitTorrent
Comcast actively blocks P2P traffic
