From uni-regensburg.de!fauern!zib-berlin.de!zrz.TU-Berlin.DE!netmbx.de!Germany.EU.net!EU.net!howland.reston.ans.net!agate!library.ucla.edu!csulb.edu!paris.ics.uci.edu!ucivax!gateway Tue Apr 5 16:27:38 1994 Path: uni-regensburg.de!fauern!zib-berlin.de!zrz.TU-Berlin.DE!netmbx.de!Germany.EU.net!EU.net!howland.reston.ans.net!agate!library.ucla.edu!csulb.edu!paris.ics.uci.edu!ucivax!gateway From: hta@uninett.no ("Harald T. Alvestrand") Subject: Frequently Asked Questions on comp.protocols.iso.X400 - with answers Message-ID: <"aun.uninet.860:01.03.94.02.01.00"@uninett.no> Newsgroups: comp.protocols.iso.x400 Approved: usenet@q2.ics.uci.edu Lines: 349 Date: 1 Apr 94 02:01:50 GMT 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. The latest revision is also available from the FTP site ftp://aun.uninett.no/pub/mail/x400faq/FAQ-mhsnews.text $Revision: 1.15 $ $Date: 1993/10/18 10:32:47 $ 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? 9) What is my X.400 address? 10) Why does mail to /..../@gateway fail? QUESTIONS AND ANSWERS 1) What is X.400? ================= X.400 is the short name for the set of standards from ISO and the ITU 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. (ITU-TS, the International Telecommunications Union Telecommunication Standard Sector, was formerly named CCITT). 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 ITU-TS. - ISO MOTIS/86 (mostly dead): This was the first attempt from ISO to agree to what ITU-TS 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? ======================================= The issue of FTPing standards is painful, to say the least, but things are improving. Currently, the ITU has set up an automatic mail responder at the address itudoc@itu.ch (C=ch;admd=arcom;prmd=itu;s=itudoc) that contains a large number of documents, including the X.400 standards that have been updated since 1992. This includes, at the moment (Sept -93), X.400, X.402, X.419 and X.435 + the "conformance testing" series (X.480 to X.482). The format is commonly PostScript and/or Word for Windows 2.0. The same information, and more, is available through Gopher at info.itu.ch; a really nice service! The press release says that "TELEDOC will be available on request, on a trial period of one year, at no access cost"; all I know for sure is that at the moment (September 1993), it is still running. If you send a message with HELP as the first word in the body, you will get a simple user guide. ISO documents cannot in general be put online. In some cases, the authors have placed copies of last-version drafts online, since drafts are not copyrighted by ISO. In other cases, special arrangements have been made to put certain ISO standards (like the CLNS spec) online. They are available (at cost) from your local standards body. Some organizations also provide subscription services and provide copies of the standards. Read the "standards FAQ" of comp.protocols.iso for more info. 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 pub/doc/ISO/english. There are a lot of files containing USENET articles and other sources of information about OSI protocols and related ISO/ITU standards. The file INDEX contains a summary of the contents. Markus Kuhn , who kindly supplied me with this information, maintains this archive. Please contact him if you have additional interesting files. Other interesting places, supplied by Markus Kuhn: ftp.uni-erlangen.de pub/doc/ISO collected USENET articles etc. osi.ncsl.nist.gov ftp.uu.net networking/osi ISODE and other OSI stuff networking/x25 nic.ddn.mil protocols DoD and GOSIP related stuff rfc RFC Repository cs.ucl.ac.uk src ISODE, PP, OSIMIS, ... osi-ds Internet X.500 documents ietf-osi-oda Internet ODA documents aun.uninett.no ietf/mhs-ds X.500 based routing drafts ftp.ifi.uio.no pub/SGML SGML/HyTime related things ftp.uni-stuttgart.de info/standards various documents info/osi-rus X.400/X.500 papers nnsc.nsf.net CCR IEEE CCR articles uu.psi.com isode ISODE 8.0 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=;ADMD=;X121=9 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=;; DD.FAX=;DD.ATTN= 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. The MAP/TOP profiles also specify (and use) X.400 for use over TP4 across any 802.x LAN (such as Ethernet or FDDI). Finally, 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 Also mentioned by: Philipp Hoschka David McAnally 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 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 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 Mentioned by Hans P. Holen 9) What is my X.400 address? If you have an Internet address of the form username@domain.name, there are two alternatives for your X.400 address: EITHER there is a defined mapping onto standard attributes for your domain, so that, for instance Harald.Alvestrand@delab.sintef.no maps to C=no;ADMD= ;PRMD=uninett;O=sintef;OU=delab;S=Alvestrand;G=Harald OR there is no such mapping, and you will have to use a Domain Defined Attribute: Someone@somewhere.com maps to ;DD.RFC-822=Someone(a)somewhere.com An IETF working document (draft-ietf-x400ops-mgtdomains-01.txt) gives the suggestion to use C=us;ADMD= ;PRMD=Internet to mean "any gateway to the Internet". This is not yet final, but might be supported on some X.400 services. It is not likely to work in commercial services. The following characers have special conversion rules when used in DDAs: @ -> (a) at sign ! -> (b) exclamation point (bang) % -> (p) percent sign _ -> (u) underscore All the hoary details may be found in RFC 1327. A more readable version is the COSINE addressing user guide, found in English and French at nic.switch.ch. FTP access: login COSINE, directory public/user-guides, file addressing-* Email access: send to cosine-mhs-server@nic.switch.ch with the body saying "SEND public/user-guides/addressing-english-291092.txt" A few places where you can use TELNET to a port, type in your address and see what it maps to, are: relay.surfnet.nl(130.161.180.100) port 4545 nic.switch.ch, login as "mailaddr" sirius.dfn.de, login as "adressen" These services are also available via X.25 PAD and e-mail; get the addressing guide mentioned above for the details. NOTE: If you use gateways that do not conform to RFC 987, RFC 1148 or RFC 1327, all bets are off. For instance, the kindest description of the result of passing through the gateways of most commercial X.400 service providers is "interesting". 10) Why does mail to /..../@gateway fail? This is a bug of long standing. Typically, you see a message like: << /...../@gateway: Cannot mail directly to files This has a long and convoluted history. Usually, it involves a mailer that knows how to do UUCP. It turns out that one program used in UUCP (uuxqt) is capable of executing a large set of commands, some of which may destroy important files if given filename arguments. So, in order to protect this from happening, HDB UUCP will follow in the tradition of fixing loose thumbtacks with sledgehammers, and refuse to accept any command that has an argument that looks like a filename that is relative to the root. In the common UUCP setup, where only rmail and rnews are permitted, this does not make sense, but it is not possible to turn it off. In Taylor UUCP, it is a compile time option. (This information supplied by Ian Lance Taylor ) Another "nice" feature that helps in causing this is the "s" flag in the Sendmail mailer definition. This strips the quotes off the local part of the address, so that "/..../"@gateway gets turned into /..../@gateway, which easily makes things go haywire. This flag should be nuked on all mailers except the "local" and "prog" mailers. Unfortunately, SUN ships it on all mailers by default, but then, anyone who uses a SUN default Sendmail configuration has problems anyway. .