Path: utzoo!utgpu!jarvis.csri.toronto.edu!rutgers!tut.cis.ohio-state.edu!ucbvax!AHWAHNEE.STANFORD.EDU!dcrocker
From: dcrocker@AHWAHNEE.STANFORD.EDU (Dave Crocker)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Reliable datagram service available? (SUMMARY)
Message-ID: <8906140633.AA04842@ucbvax.Berkeley.EDU>
Date: 9 Jun 89 22:50:09 GMT
Sender: daemon@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 13

Your quotation of Rex Buddenberg's comment that TCP requires a minimum of
9 packets to deliver one did not ring true, so I did a little background
querying.  At the moment, the contest is between 3 and 5 packets, but
certainly not 5.  (Just is case anyone thinks that this note is trying
to suggest that a reliable datagram protocol is not a good idea, don't.
It's only that 9 is such a high number, it makes TCP look unreasonable.)

The theory that suggests 3 packets says that the originator sends
a packet that contains an open(SYN), close(FIN), and the data.  The
receiver returns a packet that contains a a SYN/FIN/ACK, and the
original host then returns an ACK.  (3-way handshake.)

Dave