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From: nowicki%rose@SUN.COM.UUCP
Newsgroups: mod.protocols.tcp-ip
Subject: More on Port numbers
Message-ID: <8605162109.AA04338@rose.sun.uucp>
Date: Fri, 16-May-86 17:09:05 EDT
Article-I.D.: rose.8605162109.AA04338
Posted: Fri May 16 17:09:05 1986
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	Doesn't SUN's RPC (which I believe is in the public domain)
	address this issue (no pun intended)? If you say "do you
	seriously expect me to implement RPC and XDR just to get a port
	number?", I sympathize, I was only trying to find analogues for
	enlightenment.

Yes, Sun RPC (which was posted to mod.sources and is on the 4.3BSD
tape) has a service called the "Port mapper" that listens on one well
known port (number 111, officially registered as SUNRPC).  Other Sun
RPC services register with the port mapper, and send to this port to
get other services.  RPC "program numbers" are 32-bit integers, which
will take a while to use up. There is a map in the Yellow Pages lookup
service that maps from string name to RPC program number, so you can
add new protocols without compiling their numbers in programs.  There
also is a Yellow Pages map for finding port numbers given a string name
(like the /etc/services file in 4.x BSD).

	-- Bill Nowicki
	   Sun Microsystems