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From: piet@cwi.nl (Piet Beertema)
Newsgroups: comp.protocols.tcp-ip.domains
Subject: Re: Proposal for use of DNS to store RFC 987, etc mappings
Message-ID: <9007271620.AA29144@piring.cwi.nl>
Date: 27 Jul 90 16:20:37 GMT
References: <9007270026.AA16028@bel.isi.edu>
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	I thought that RFC-987 was for mapping between the Internet mail
	protocol as defined in RFCs 821 and 822, and the X.400 mail system.
Correct.

	If that is the case then wouldn't any gateway that did RFC-987 be
	between the Internet and some part of the X.400 world?
Definitely not: mapping between a protocol and some other
world does not necessarily imply gatewaying between one
particular network and some other world, even when that
network happens to be the originator and largest user of
that particular protocol.

	That is, won't any gateway that needs to do the RFC-987 mappings have
	one foot in the Internet, and therefore have access to the DNS?
No. Gateways following RFC-987 may well operate between
parts of the X.400 world and networks that are using the
"Internet mail protocol as defined...." but that do not
necessarily have access to the Internet and thus to the
Internet-wide DNS.


	Piet