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From: jg@max.crl.dec.com (Jim Gettys)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Nagle algo. in Unix-TCP
Keywords: tcp tinygram RPC X11
Message-ID: <643@crltrx.crl.dec.com>
Date: 6 Sep 89 20:45:53 GMT
References: <13394@well.UUCP> <2581@lll-lcc.UUCP>
Sender: news@crltrx.crl.dec.com
Organization: Digital Equipment Corporation, Cambridge Research Laboratory
Lines: 17

As noted, 4.3BSD has a socket option to defeat delayed ACK's,
specifically put there on our request
(X happened to be the first application to run into the problem, during
beta test of 4.3, back well
before X11).

This has been picked up by essentially everyone.  Ultrix had the option
since V2 days.

The option (found in /usr/include/netinet/tcp.h) is TCP_NODELAY.

/*
 * User-settable options (used with setsockopt).
 */
#define TCP_NODELAY     0x01    /* don't delay send to coalesce packets */

				- Jim Gettys