Use of the EAN service from a UK site _1_. _O_v_e_r_v_i_e_w This document gives a brief introduction of EAN together with a description of the way messages may be sent to, or relayed through EAN. Included in this document are guide- lines for locating EAN users and UK domains, together with a help section regarding EAN mail problems. Please refer to the document ean.sites, for a list of EAN domains and sites reachable from UCL. _2_. _I_n_t_r_o_d_u_c_t_i_o_n There are two types of Message systems currently being used within UCL. The first type is the older text message sys- tem, MMDF II, based on the RFC822 protocol, and the second is an X400 system called EAN which was produced by the University of British Columbia for the UNIX and VAX/VMS sys- tems. The message system MMDF II supports amongst other protocols, both the DARPA Simple Mail Transfer Protocol (SMTP) [Postel82] and the UK Joint Network Team (JNT) Mail Protocol (Grey Book) [Kille84], and hence interconnects with the JANET, PSS and DARPA networks. The X400 EAN network has now become accessible to the JANET, PSS and DARPA networks by interfacing with MMDF II through an RFC/X400 gateway. At present the RFC822/X400 gateway offers a pilot service, and can currently be used between Grey Book Systems that are correctly registered in the NRS (Name Registration Scheme) and EAN systems inside/outside the UK Academic Community. There is currently no authorisation required to use the gateway, though this will be reconsidered if usage increases beyond the fixed budget for volume tariffs. The next sec- tion describes how messages should be addressed when being sent to EAN users or relayed through EAN to other remote message systems via the RFC822/X400 gateway. March 4, 1986 - 2 - _3_. _A_d_d_r_e_s_s_i_n_g For those readers unfamiliar with mailbox addressing, please read Appendix A - An Introduction to mailbox addressing. To send to, or relay a message through, EAN one or more mailboxes must be specified. A mailbox can be addressed in one of two ways: 1) local-part@domain-1 2) local-part%domain-2@domain-1 Within the UK Academic Community, domains are defined by the Name Registration Scheme (NRS) [Larm83], and are hierarchi- cally structured with "." (full stop) as a seperator. The top of the hierarchy is on the Left Hand Side. This order- ing is sometimes known as big-endian (most significant first). Example domains would be: UK.AC.SALFORD.R-D UK.AC.NOTTINGHAM.MATH This is different from the DARPA Internet and the EAN domain specifications, where the syntax is identical to the NRS but the ordering of the hierarchy is reversed. That is little- endian (least significant first). Example domains would be: ALBERTA.CDN UNIGE.CHUNET GMD.DFN CHALMERS.SUNET Users making full use of the NRS can send messages to an EAN mailbox by specifying the domains big-endian. For example: EAN mailboxes having the following addresses: james@VAX.RUNIT.UNIT.UNINETT james@XPS.GMD.DFN james@CSVAX.UCD.IRL james@IASI.CNR.OSIRIDE should be addressed by the UK Academic Community as: james@UNINETT.UNIT.RUNIT.VAX james@DFN.GMD.XPS james@IRL.UCD.CSVAX james@OSIRIDE.CNR.IASI EAN users wishing to send mail to a JANET mailbox would need to specify the domains little-endian. March 4, 1986 - 3 - For example: JANET mailboxes having the following addresses: james@UK.AC.UCL.CS james@UK.AC.RUTHERFORD.GEC-B james@UK.AC.OXFORD.PHYSICS.DEC10 james@UK.AC.CAMBRIDGE.PHOENIX should be addressed by EAN as: james@CS.UCL.AC.UK james@GEC-B.RUTHERFORD.AC.UK james@DEC10.PHYSICS.OXFORD.AC.UK james@PHOENIX.CAMBRIDGE.AC.UK JANET users wishing to send mail to the EAN network may need to use the mailbox address 2 format (see above), if their message systems cannot route on the basis of Top-level domains. For example: EAN mailboxes having the following addresses: james@VAX.RUNIT.UNIT.UNINETT james@IASI.CNR.OSIRIDE james@EAN.VAX2.CS.UCL.AC.UK james@MUNNARI.MU.AUS may be addressed by the UK Academic Community as: james%UNINETT.UNIT.RUNIT.VAX@UK.AC.UCL.CS james%OSIRIDE.CNR.IASI@UK.AC.UCL.CS james%UK.AC.UCL.CS.VAX2.EAN@UK.AC.UCL.CS james%AUS.MU.MUNNARI@UK.AC.UCL.CS March 4, 1986 - 4 - _4_. _G_u_i_d_e_l_i_n_e_s _f_o_r _l_o_c_a_t_i_n_g _E_A_N _u_s_e_r_s Included within the lists of domains and sites, in (please refer to) ean.sites, are the addresses of Contact Persons, who you may send a message to, regarding any user queries belonging to that Top-level domain, its Lower-level domains and sites. _5_. _G_u_i_d_e_l_i_n_e_s _f_o_r _l_o_c_a_t_i_n_g _U_K _d_o_m_a_i_n_s There is a list of avaliable UK domains and sites (in NRS order), which can be obtained by mailing a request to the following address: liaison@uk.ac.ucl.cs _6_. _H_e_l_p Any UCL EAN queries should be sent to: liaison@uk.ac.ucl.cs Any problems that are specific to EAN mail should be sent to: ean-postmaster@uk.ac.ucl.cs March 4, 1986 - 5 - Glossary Address - A string used to specify the location of a mailbox. For example: James Hacker DARPA - The Defense Advanced Research Projects Agency. Domain - A hierarchically structured string specifying an organisation. Examples of domains are UK, ARPA, UUCP, UK.AC USC-ISID.ARPA. If a domain is sufficiently specified it is possible to identify a direct connection to a site, which may be associated with that domain or be a relay to that domain. Host - A computer connected to a network. JANET - The Joint Academic Network. This is the private packet switched network managed by the JNT for the academic community in the UK. JNT - The UK Joint Network Team, sponsored by the Computer Board and SERC to manage academic network developments Mailbox - A mailbox is the source or destination of a message, often associated with a human user. A mailbox can be globally specified in RFC822 as local-part@domain NRS - The JNT Name Registration Scheme, which registers domain names for the UK Academic Community. Relay - A domain which is used to forward terminal characters files or electronic mail. Route - A route is an expilcit sequence of domains over which a message should traverse. SERC - The Science & Engineering Research Council in the UK. Site - A location of one or more hosts, where the mail is transparently delivered to one of the hosts. March 4, 1986 - 6 - Appendix A - An Introduction to mailbox addressing To send to, or relay a message through, a message system one or more mailboxes must be specified. In many cases a mailbox is associated with a file on a specific computer (host), which in turn is associated with a user. However, a mailbox could also be a distribution list which has a number of mailboxes (usually user mailboxes) associated with it. When a message is sent to a distribu- tion list, the message is delivered to all of the mailboxes specified in the distribution list. It is not possible to tell if a given mailbox is a distribution list or associated with a specific user. A mailbox can be addressed in one of two ways: 1) local-part@domain-1 2) local-part%domain-2@domain-1 In mailbox address 1 above, the domain specifies the organi- sation with which the mailbox is associated, and the local- part identifies the mailbox within the organisation. For example in the mailbox "james@KENT.WIDGET-CO", the local part is "james", and the domain "KENT.WIDGET-CO". For a message to arrive at a particular mailbox (either locally or remotely) a route for that message is required. This route is determined by the domain specified for that mailbox address (see 1 and 2 above). If a domain is defined as a hierarchically structured string specifying an organisation, examples of domains would be: UK UK.AC UK.AC.UCL Where, UK, UK.AC (Academic Community), and UK.AC.UCL (University College London), would all be organisations. But the organisation UCL would be a sub-sub-organisation within the UK, and a sub-organisation within the AC. The UK organisation can therefore be thought of as a Top-level domain with Lower-level domains AC and UCL. If for example a message originating from outside the UK has the mailbox address "james@UK.AC.UCL.CS", the message would be relayed by a remote message system to the UK domain (organisation) which would then relay the message to the AC domain which would then relay the message to the UCL domain which would then finally relay the message to the site CS (Computer Sci- ence), which would then put the message into mailbox james (assuming that this mailbox was not a list). Therefore it can be seen that there is a mapping between the March 4, 1986 - 7 - domain part of the mailbox address and a site. The mailbox address 2 (see previous mailbox address for- mats), should only be used if the originators mail system cannot interpret domain-2 but domain-1 (or site-1) does. If for example, a message system on JANET is unable to inter- pret a message having the EAN mailbox address "james@VAX.RUNIT.UNIT.UNINETT", then the message would need to be relayed to a site which does interpret this mailbox address, to do this the mailbox address 2 format is used. Using this format, the mailbox address from JANET, may for example look like: "james%UNINETT.UNIT.RUNIT.VAX@UK.AC.UCL.CS" which means that it would be routed to site UK.AC.UCL.CS which would then relay the message to domain UNINETT for the mailbox "james@VAX.RUNIT.UNIT.UNINETT". Sometimes the local-part of the mailbox address has little resemblance to actual name of the user. For instance James Hacker might have his address as "ja12@UK.AC.CAMBRIDGE.PHOENIX" a comment may therefore be used to make it simpler to understand. Thus James's mailbox addresses may have the format: comment James Hacker or James Hacker March 4, 1986 - 8 - References Kille[84] S.E.Kille, (editor), JNT Mail Protocol (revision 1.0), Joint Network Team, Rutherford Appleton Laboratory (March 1984). Larme[83] J. Larmouth, "JNT Name Registration Technical Guide", Salford University Computer Centre (May 1983). Postel[82] J.B. Postel, "Simple Mail Transfer Protocol", RFC821 (August 1982). March 4, 1986