a TCP slowstart question
Lloyd Wood <L.Wood@surrey.ac.uk> Tue, 02 November 1999 12:31 UTC
Date: Tue, 02 Nov 1999 12:31:03 +0000
From: Lloyd Wood <L.Wood@surrey.ac.uk>
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Subject: a TCP slowstart question
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[prompted by a chat with Tony Ballardie.] Has anyone looked at implementing what works in fast recovery in slow start itself? http://search.ietf.org/internet-drafts/draft-floyd-cong-00.txt Section 9.1 'Issues that have not been addressed in the standards process, and are generally considered not to require standardization, include such issues as the use (or non-use) of rate-based pacing,and mechanisms for ending slow-start early, before the congestion window reaches ssthresh.' If you experience loss due to timeout in the actual slowstart process, then the value of ssthresh must be too high for the network conditions, and should be lower. It might make sense for the individual flow to immediately enter congestion avoidance from a lower functional window size that appeared to work, skipping the doubling process all the way from 1 - this should prevent TCPs starving because they never reach ssthresh, decreasing burstiness. This is presuming that a single loss due to timeout in slowstart is equivalent to three dupacks in congestion avoidance. This fits with proposals for increasing initial window size, I think, which address the same starting-from-1-segment going-back-to-1-segment with less flexibility in the case of loss during slowstart. Pointers/list of obvious pitfalls welcome. thanks, L. <L.Wood@surrey.ac.uk>PGP<http://www.ee.surrey.ac.uk/Personal/L.Wood/>
- a TCP slowstart question Lloyd Wood
- Re: a TCP slowstart question Neal Cardwell