From: Eric Dumazet <dada1@cosmosbay.com>
To: netdev@oss.sgi.com
Subject: Three way TCP handshake : can we avoid the third packet ?
Date: Tue, 21 Sep 2004 11:47:43 +0200 [thread overview]
Message-ID: <414FF8BF.4070302@cosmosbay.com> (raw)
Hi
I discovered today that some TCP stackes are able to initiate TCP
sockets with 2 packets "only".
The third packet (ACK packet) is just delayed and integrated into the
data packet.
11:07:15.551507 host1.11906 > host2.80: S 1522618044:1522618044(0) win
64240 <mss 1452,nop,nop,sackOK> (DF)
11:07:15.551523 host2.80 > host1.11906: S 751859039:751859039(0) ack
1522618045 win 5840 <mss 1460> (DF)
11:07:16.112451 host1.11906 > host2.80: P 1:92(91) ack 1 win 65340
11:07:16.151800 host2.80 > host1.11906: . ack 92 win 5840 (DF)
It seems to be valid (host2 is linux in this tcpdump output), and saves
one packet.
Is it possible to achieve the same thing with linux 2.4/2.6 ?
A magical setsockopt() thing like TCP_CORK, TCP_QUICKACK, after the
socket() call and before the connect() ?
Thank you
Eric Dumazet
next reply other threads:[~2004-09-21 9:47 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2004-09-21 9:47 Eric Dumazet [this message]
[not found] <41504117.9010108@cosmosbay.com>
[not found] ` <Pine.LNX.4.61.0409211838390.31157@filer.marasystems.com>
[not found] ` <415136D1.7030600@cosmosbay.com>
2004-10-12 8:15 ` Three way TCP handshake : can we avoid the third packet ? Eric Dumazet
2004-10-12 8:38 ` Eric Dumazet
2004-10-12 8:41 ` Henrik Nordstrom
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