<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.0 Transitional//EN"> <HTML><HEAD> <META content="text/html; charset=utf-8" http-equiv=Content-Type> <META name=GENERATOR content="MSHTML 8.00.6001.18812"> <STYLE></STYLE> </HEAD> <BODY> <DIV><FONT size=2 face=Arial>"PxYra" <</FONT><A href="mailto:nera@nebus.net"><FONT size=2 face=Arial>nera@nebus.net</FONT></A><FONT size=2 face=Arial>> wrote in message </FONT><A href="news:h5rl9l$7r9$1@trimpas.omnitel.net"><FONT size=2 face=Arial>news:h5rl9l$7r9$1@trimpas.omnitel.net</FONT></A><FONT size=2 face=Arial>...</FONT></DIV> <DIV><FONT size=2 face=Arial>> <BR>> daugiau kuo shustresne versija tada ir vaidenas visokie leti uzsieniai P2P <BR>> ribojimai ir kitos nesamones, <FONT color=#ff0000 size=5> ? ? ?</FONT></FONT></DIV> <DIV><FONT color=#ff0000 size=5 face=Arial></FONT> </DIV> <DIV>HOW IT WORKS:<BR><BR>- The Sandvine application reads packets that are traversing the network boundary<BR><BR>- If the application senses that outbound P2P traffic is higher than a threshold determined by Comcast, Sandvine <STRONG><FONT color=#ff0000>begins to interrupt P2P protocol </FONT></STRONG>sequences that would initiate a new transfer from within the Comcast network to a peer outside of the Comcast network<BR><BR>- The interruption is accomplished by sending a perfectly forged TCP packet (correct peer, port, and sequence numbering) with the RST (reset) flag set. This packet is obeyed by the network stack or operating system which drops the connection.<BR><BR>In eDonkey connections, for example, queued UPLOADS (to others) will not be honored to some percentage of non-Comcast P2P users. <STRONG><FONT color=#ff0000>Immediately</FONT></STRONG> after the peer requests ranges to be transferred, <STRONG><FONT color=#ff0000>the connection is dropped in the above manner</FONT></STRONG>. Gnutella transfers are similarly affected in the same manner.<BR><BR>In BitTorrent connections, the RST message is sent well after the handshake, and often after some data has been exchanged. The Sandvine filter interferes during lulls (NOOP and HAVE commands) as well as the moment of transition from the ending of sending one complete piece. When I am not using Comcast, BitTorrent disconnections due to peer resets (RST flag) are 3%. Using Comcast, 39% of connections are terminated using the RST flag.<BR><BR>In Summary: The Sandvine filter has taken steps to try to make the filtering experience innocuous (nearly invisible) to the user. Some transfers are allowed, the interruption seems to come from the distant peer, and it relies on the P2P protocol being used to either find another peer (hopefully a Comcast one) or retry that peer later.</DIV></BODY></HTML>