Path: utzoo!mnetor!uunet!husc6!mit-eddie!ll-xn!ames!sri-spam!distek4!mckenney
From: mckenney@distek4..istc.sri.com (Paul E. McKenney)
Newsgroups: comp.protocols.tcp-ip
Subject: Re: Pseudo-Headers & Checksumming
Message-ID: <11117@sri-spam.istc.sri.com>
Date: 11 Jan 88 17:42:48 GMT
References: <8801110746.AA18699@Pescadero> <8801111505.AA02117@percival.cs.purdue.edu>
Sender: nobody@sri-spam.istc.sri.com
Reply-To: mckenney@tsca.istc.sri.com (Paul E. McKenney)
Organization: SRI International
Lines: 20

In article <8801111505.AA02117@percival.cs.purdue.edu> narten@PURDUE.EDU
(Thomas Narten) writes:
>Is ICMP useful to newer protocols, and if not, can the Internet
>operate effectively without it?

Better yet:  Can ICMP be used by newer protocols that cannot fit the
source information into eight bytes?

High-speed hosts with lots of memory to burn could use the IP
`Identification' field to help match ICMP replies with recently-sent
packets, but only as long as they never send more than 65536 packets per
RTT.  This would not interfere with the normal use of this field (as an
aid in reassembling datagrams).  Furthermore, a host could unilaterally
make this use of the field, no cooperation is required.

If it is necessary to support more than 65536 packets per RTT, a new IP
OPTION field analogous to the SATNET `Stream Identifier' could be defined --
at a cost of an additional 32 to 64 bits per packet, of course!

				Thanx, Paul