Path: utzoo!mnetor!uunet!husc6!mailrus!nrl-cmf!ames!pasteur!ucbvax!A.ISI.EDU!CERF
From: CERF@A.ISI.EDU
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Acking out-of-order packets?
Message-ID: <[A.ISI.EDU].3-Mar-88.00:44:19.CERF>
Date: 3 Mar 88 05:44:00 GMT
References: <8803030258.AA23633@ucsd.edu>
Sender: usenet@ucbvax.BERKELEY.EDU
Organization: The Internet
Lines: 11

My recollection of intent in RFC 793 was to have the TCP invite
the proper next packet by responding with the "next packet" ACK
and not with an ACK that references anything about the out of order
packet. 

Perhaps others will either remember differently or have a better
notion for how to behave under the circumstances described.
Obviously, if TCP had "out of order" acking and selective
retransmission, the response would be more complex.

Vint