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From: craig@LOKI.BBN.COM (Craig Partridge)
Newsgroups: mod.protocols.tcp-ip
Subject: re: Port Collisions
Message-ID: <8605140213.AA06443@ucbvax.Berkeley.EDU>
Date: Tue, 13-May-86 22:16:39 EDT
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Posted: Tue May 13 22:16:39 1986
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> We here at Symbolics are concerned with the process of assigning TCP/UDP
> port numbers.  It is not always appropriate for us (and other vendors)
> to apply for ports in the Czar-controlled first 256 ports.  Either
> because of time constraints or issues of proprietary information, we
> cannot always write and distribute an RFC for each of our protocols.

Why not make the port numbers used user/site configurable?  Berkeley
actually did this quite nicely with a services list, which mapped
a service name/protocol pair with a port number.  Since programs
use this database (or are supposed to) to find out what port they
are supposed to us, one could run SMTP on TCP port 25 on the Internet
but port 243 on some private network if one so chose.

The advantage is the vendor need not necessarily worry about what
port you pick for your special application -- it can always be
changed among cooperating machines.

Craig Partridge
CSNET Technical Staff