From: Harald.T.Alvestrand@delab.sintef.no
Subject: Frequently Asked Questions on comp.protocols.iso.X400 - with answers
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This is the Frequently Asked Questions file for
the mailing list MHSNEWS/newsgroup comp.protocols.iso.X400

It is sent to the list on the first of every month.

$Revision: 1.9 $
$Date: 1992/08/16 19:46:37 $

CURRENT QUESTIONS

1) What is X.400?
2) How does X.400 compare to SMTP?
3) What X.400 implementations are available?
4) Where can I FTP the X.400 standards?
5) Where can I find more information about X.400 and OSI?
6) How do I send to Telefax from X.400?
7) On which type of network may I use X.400
8) What books can be recommended on X.400?

QUESTIONS AND ANSWERS

1) What is X.400?
=================
X.400 is the short name for the set of standards from ISO and the
CCITT that describe a mail service.
It is the only non-proprietary standard for interchange of electronic
mail that has the sanction of an official standards body.

It currently exists in 3 flavours:

- X.400/84: This is what most implementations today in fact run.
  It was documented in the "Red Book" series from CCITT.

- ISO MOTIS/86 (mostly dead): This was the first attempt from ISO to
  agree to what the CCITT had done. It died at the DIS stage.
  It contains some elements you need in order to conform to the
  European functional profiles and make manageable systems from the
  1984 version, like domain-internal trace and the ISO6937 body part.

- X.400/88: This is documented in the "Blue Book" series.
  Most people seem to think that this is a great improvement over 84,
  but the number of systems implementing it has been underwhelming.
  This one is also an International Standard by ISO.

2) HOW DOES X.400 COMPARE TO SMTP?
==================================
This depends on what you are asking for.

SMTP has got:
- Simplicity
- Wide acceptance
- Public domain implementations
- Public domain user interfaces

X.400 has got:
- Acceptance in the standards communities
- Commercial vendors of service
- Defined ways to transfer things other than ASCII text
  (but only a few implementations have implemented it)
- Standard notifications of delivery to user's mailbox and notification
  of a message being read by the user (these ones are often implemented, too!)

3) WHAT X.400 IMPLEMENTATIONS EXIST?
====================================

The answer to this question formed the largest and fastest-changing part
of the FAQ; it is now sent out as a separate message. It should be the
one immediately following this one.

4) Where can I FTP the X.400 standards?
=======================================

Officially, you can't.
The OSI community has a large number of organizations that derive
revenue from *selling* copies of these standards.

The CCITT, not being funded in that way, made an experiment in which
they made all the CCITT documents available for anonymous FTP, but
that experiment terminated on December 31, 1991, to be replaced by a
service run out of the ITU offices in Geneva at some later date.

The net result is that there are a lot of electronic copies out there,
but it is not legal to make them available for anonymous FTP after
December 31, 1991.

Note: This applies ONLY to the CCITT documents; ISO standards have
never been put on the network.

5) Where can I find more information about X.400 and OSI?
=========================================================
There is various information on the FTP server at Uni-Erlangen:

     ftp ftp.uni-erlangen.de

and log in as "anonymous" with your e-mail address as password.
Look in the directory portal/doc/ISO/english. There are a lot of
files containing USENET articles and other sources of information
about OSI protocols and related ISO/CCITT standards. The file
INDEX contains a summary of the contents.

Markus Kuhn <mskuhn@immd4.informatik.uni-erlangen.de>, who kindly
supplied me with this information, maintains this archive. Please
contact him if you have additional interesting files.

6) How do I send Telefax from X.400?
====================================

The answer, as usual, is "ask your service provider".
The most common schemes:

- The standardized one: C=<country>;ADMD=<service provider>;X121=9<telephone>
  Unfortunately, this ignores the fact that 99.9% of all fax machines are
  multiuser machines, which makes it useless for mailing list purposes; there
  is no way to tell the recipient who it is for.
- The DDA one: C=<country>;<a lot of other attributes>;
               DD.FAX=<telno>;DD.ATTN=<name>
  A lot of variants are turned on this; but it fulfils the USER requirements.
- Another variant (used by PRIME) is to allow S and G attributes in the
  O/R name instead of having a DD.ATTN attribute.

7) ON WHICH TYPE OF NETWORK MAY I USE X.400
===========================================

  X.400 '84 has been defined to run over a standard OSI stack (X.25,
TP0, BAS Session), thus most implementations, and all that pass
conformance tests, are able to run over a X.25 network. Often these
implementations have a X.25 or a transport level interface with
manufacturers supplied lower layers. In the case of transport-level,
X.400 is thus able to run over CLNS as long as this is supported under
the Tli or XTi.
  However, in order to enable use of TCP/IP network, many
implementations offer RFC1006 ( TP0 over TCP/IP) access. This is
almost mandatory within TCP/IP based LAN and a real plus for the R&D
community which maily use TCP/IP WANs.
  Additionaly a few implementations such as PP/ISODE and M.PLUS/UCOM.X
come along with an RFC1006 TS-bridge which act as a relay between
X.25 and TCP/IP network for OSI applications such as X.400 and
X.500.
  Finaly many X.400 implementations for PCs or Mac have been developped
to use what exists in the PC arena such as PC-NFS, NETBios, X.32
or even dialup over modems. Carefully check what is available with
your favourite supplier!


8) WHAT BOOKS SHOULD I READ ON X.400?
=====================================

In spite of the large interest on the topic, there does not seem to be
many specific X.400 books around.

The ones that have been mentioned are:

  X400 Message Handling, Standards, Interworking, Applications
  by B. Plattner, C. Lanz, H. Lubich, M. M"uller and T. Walter
    of the Swiss Federal Institute of Technology (ETH), Zurich
  It was translated by Stephen S. Wilson
  Published by Addison-Wesley, 1991, data communications and networks series
  ISBN 0-201-56503-X
  Price approximately USD 41

  The German edition is named:
  Elektronische Post und Datenkommunikation:
  X.400: Die Normen und ihre Anwendung.
  Bonn: Addison-Wesley, 1989

  It includes:
  - Basics of the OSI reference model and the X.400 MHS model
  - Stuff about interworking (mentioning RARE MHS!), EDI and more
  - Improvements of X.400 from 84 to 88, and the problems in interworking
  - A lot of useful appendices.

Information by Marcel Mink <M.J.Mink@fel.tno.nl>
Also mentioned by:
Philipp Hoschka <Philipp.Hoschka@sophia.inria.fr>
David McAnally <ACUS02@WACCVM.corp.mot.com>


  Carl-Uno Manros
  The X.400 blue book companion
  Twickenham: Technology Appraisals, 1989.
  ISBN: 1-871802008

  Not very detailed, but helps if one also reads the standard "in parallel".

Information by Philipp Hoschka <Philipp.Hoschka@sophia.inria.fr>

  Robert Babatz, Manfred Bogen und Uta Pankoke-Babatz
  Elektronische Kommunikation - X.400
  Braunschweig: Vieweg, 1990.
  ISBN: 3-528-06389-0

  Very helpful, but in German. There might be plans for
  an English edition, though.

Information by Philipp Hoschka <Philipp.Hoschka@sophia.inria.fr>

  Sara Radicati
  Electronic Mail, an introduction to the X.400 Message Handling Standards
  McGraw-Hill 1992 (Uyless Black series on computer communication)
  ISBN: 0-07-051104-7

  Fairly comprehensible and readable. A good introductory text

Information by Erik Skovgaard <eskovgaa@cue.bc.ca>
Mentioned by Hans P. Holen <h.p.holen@usit.uio.no>
.
Newsgroups: comp.protocols.iso.dev-environ