Date: Fri, 20 Sep 2002 20:56:44 -0500 (CDT) From: Mike Silbersack <silby@silby.com> To: Julian Elischer <julian@elischer.org> Cc: net@freebsd.org Subject: Re: Tcp question. Message-ID: <20020920204805.G6326-100000@patrocles.silby.com> In-Reply-To: <Pine.BSF.4.21.0209201718100.21069-100000@InterJet.elischer.org>
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On Fri, 20 Sep 2002, Julian Elischer wrote: > OK so I have 3 machines: > > > A------router--------B-------router--------C > > > if I send data from B to A I see 7MB/sec. > if I send data from B to C I see 700KB/sec > > tcpdump shows some odd behaviour in the slow link: > (tcpdump run from (B)) Could you repost with more of the timestamp intact? It's really hard to read as is. > 000221 C.ssh > B.916: . [tcp sum ok] ack 66194 win 24624 > nop,nop,timestamp 259781842 16260556> (DF) > (ttl 64, id 18252, len 52) > **why wait here**? > 003030 C.ssh > B.916: . [tcp sum ok] ack 68930 win 24624 > nop,nop,timestamp 259781842 16260556> (DF) > (ttl 64, id 18253, len 52) > 000279 C.ssh > B.916: P 3769:3813(44) ack 70298 win 24624 > nop,nop,timestamp 259781842 16260556> (DF) > (ttl 64, id 18254, len 96) Hm, the TCP stack doesn't look like it thinks that it's waiting... the timestamps don't seem to be incrementing. Of course, since I can't see the timestamp, I don't know what waiting means. :) Have you tried disabling delayed acks just to be doubly sure that the delayed ack code isn't causing the problem somehow? Also, is C really a FreeBSD box? I didn't think we used window sizes of 24K. Mike "Silby" Silbersack To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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