Hello All, I am a researcher at Ohio University looking to encapsulate a special point-to-point Delay Tolerant Networking protocol in DCCP instead of UDP to take advantage of DCCP's congestion control. In attempting to set this up I have come across some very odd behavior from DCCP. My goal is to open one DCCP connection and then keep it open even when the encapsulated protocol is idle (this avoids having a three-way handshake for every packet sent). However, in my tests, DCCP clamps the sending rate down to three packets per second after a short idle period (a few seconds) and then never attempts to increase that rate. This seems to be a very unusual and counter-intuitive behavior. Has anyone else seen similar behavior? This seems to contradict RFC4341 section 5.1 which says that CCID2 should slow start after an idle period. Is this not implemented yet or is it a bug? My test machines are running Ubuntu 10.04. Uname -a "2.6.32-24-generic-pae #38-Ubuntu SMP Mon Jul 5 10:54:21 UTC 2010 i686 GNU/Linux". I have seen identical behavior with Ubuntu 9.10 (Linux 2.6.31). I'm using CCID2 "TCP-like Congestion control" since I want as much bandwidth as possible, even if that means rapid fluctuations. Thanks. Sincerely, Samuel Jero -- To unsubscribe from this list: send the line "unsubscribe dccp" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
