On Tue, Aug 12, 2008 at 10:17:32AM -0400, Henning Schulzrinne wrote: >> - In congested networks > > The SCTP congestion control algorithm is essentially the same as TCP, so > there's no advantage. Unfortunately, there seems to be a fair amount of > mystique around SCTP which isn't borne out by the observable facts.
There might be subtle differences, e.g., whether one counts acknowledged packets or bytes, and there may be implementation specific "optimizations", which cause observable performance differences. Some time ago I measured signaling message transmission delays over an uncongested link with synthetic packet losses. For medium to high message rates, Linux SCTP with one stream and ordered(!) transmission (i.e., TCP-like transport) caused significantly smaller delays than Linux TCP, and was closer to the values calculated using a model of fast retransmit and head-of-line blocking. For lower message rates TCP performed better. Seeking for explanations one has to deal with issues such as usage of ABC, or deriving RTO from RTT estimates, etc. Coming back to the original question, I also doubt that one would see advantages in the real world, which justify the additonal effort. regards, Sebastian -- Sebastian Kiesel mailto:[EMAIL PROTECTED] Network Research Division tel:+49-6221-4342-232 fax:+49-6221-4342-155 NEC Laboratories Europe Kurfuerstenanlage 36, 69115 Heidelberg, Germany -- NEC Europe Limited Registered in England 2832014 Registered Office NEC House, 1 Victoria Road, London W3 6BL _______________________________________________ P2PSIP mailing list [email protected] https://www.ietf.org/mailman/listinfo/p2psip
