Handbook of Infosec Terms 2.0/Handbook_of_Infosec_Terms_Version_2.0_ISSO.iso/text/rfcs/rfc1616.txt

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Network Working Group                          RARE WG-MSG Task Force 88 Request for Comments: 1616                                      May 1994 RARE Technical Report: 10 Category: Informational

      X.400(1988) for the Academic and Research Community in Europe

            A report by the RARE Task Force on X.400(1988)              of the RARE Working Group on Mail & Messaging

Status of this Memo

   This memo provides information for the Internet community.  This memo    does not specify an Internet standard of any kind.  Distribution of    this memo is unlimited.

1.  Abstract

   The European research and development community, as represented by    the member research networks of RARE, has lead the deployment within    the global R&D community of X.400 electronic messaging services, as    specified in the international recommendations CCITT X.400(1984), for    more than five years. As a result of providing such services to the    European R&D users it has become clear that there is an existing and    ever increasing demand from these users for new and enhanced    electronic messaging services and product to be used to communicate    within the R&D community but within commercial service providers and    organisations as well.

   It is also clear that new services, such as Multimedia messaging and    Secure messaging, and the resulting products promise dramatic    benefits and opportunities, for not only the R&D community but also    for the wider commercial, industrial and public communities, in terms    of facilitating innovative ways of working and living which can only    enhance the missions and goals of the respective communities. Not    least the establishment of globally pervasive messaging services    between all users, R&D and commercial, is facilitated by the early    adoption of such advanced new services. An indication of the    importance of such a messaging service can be appreciated if one    considers that in many organizations (especially commercially based)    messaging may be the only method to communicate between independent    organizations due to security considerations and lower layer network    differences.

   The Commission of European Communities (CEC) VALUE subprogram II has    been established to support initiatives relating to the development    and adaptation of R&D networks in member states.  Amongst other



RARE WG-MSG Task Force 88                                       [Page 1]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    initiatives the VALUE program supports X.400 initiatives in certain    countries. VALUE support has so far been limited to X.400(1984)    initiatives, as X.400(1984) has up until now been the dominating OSI    services. However as X.400(1988) implementations have started to    appear a VALUE funded study of the X.400(1988) aspects of messaging    and their impact on the R&D community was felt necessary. This report    is one of the results of that study.

   The report documents the results of a task force on X.400(1988)    deployment of the RARE Mails and Messaging Work Group during the    period from November 1992 until October 1993. Open reviews of the    report have occurred in the RARE Mail and Messaging Work Group and    within the IETF X.400ops Working Group.

   The scope of the report is limited to deployment of X.400(1988)    services, and as such the report does not contain any recommendations    on development and deployment of Internet RFC 822 / MIME/ PEM related    (pilot) services. However, since the report shows that both    X.400(1988) and RFC 822 / MIME / PEM will be developed and used    within the European R&D community, such a pilot should also    considered.  Note: RFC 822 is also known as Internet STD 11.

   Circulation of this report is unlimited. Comments on this report may    be sent to the e-mail distribution list:

    RFC 822: [e-mail]     X.400:   S=wg-msg;O=rare;P=surf;A=400net;C=nl;

Task Force Members:

    Claudio Allocchio (INFN),     Harald T. Alvestrand (SINTEF),     James C. I. Craigie (JNT),     Urs Eppenberger (SWITCH),     Frode Hernes (maXware),     Jeroen Houttuin (RARE),     Erik Huizer (SURFnet) - chairman,     Steve Kille (ISODE Consortium),     James A. (Jim) Romaguera (NetConsult).

    Editors: James A. (Jim) Romaguera & Erik Huizer

   The work of this Task Force has been funded by the Commission of    European Communities (CEC) VALUE subprogram II, Stichting SURF and    SURFnet bv.





 RARE WG-MSG Task Force 88                                       [Page 2]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 Table of Contents

   1.  Abstract                                                      1    2.  Management Summary                                            3    3.  Framework for the report                                      6    4.  Present situation of European Messaging                       7       4.1. Messaging services                                        7       4.2. Requirements for messaging                                8              4.2.1. User Oriented                                    9              4.2.2. Service provider viewpoint                      10       4.3. Messaging capabilities                                   11    5.  Possible solutions for providing globally pervasive        messaging                                                    12       5.1. PC LAN E-mail systems                                    13       5.2. RFC 822, MIME and PEM services                           15       5.3. X.400 - 1984 and 1988                                    19    6.  Migration to X.400(1988)                                     23       6.1. PC LAN E-mail systems                                    25       6.2. RFC 822, MIME and PEM services                           25       6.3. X.400(1984) services                                     27       6.4. Mail-11 services                                         28    7.  Benefits of migrating to X.400(1988) and the involved costs  28    8.  Main Recommendations                                         33    9.  Security Considerations                                      34    10. Reading List and Bibliography                                35    11. Terminology                                                  37    Appendix A - Elaboration on the main recommendations             38    Appendix B - A number of detailed guidelines.                    40    Authors' Addresses                                               44

2.  Management Summary

   This document reports the results of study of the X.400(1988) aspects    of messaging and their impact on the R&D community. The study was    funded by the CEC under VALUE Subprogram II and has been carried out    by a task force on the RARE Mail Working Group.  The document is    targeted at technical decision makers as well as those who would fund    activity in this area.

   The document presents the existing situation as regards the    predominate messaging technologies within Europe. These are presented    within the context of a number of large messaging communities that    are using these technologies:

    - RFC 822,     - X.400(1984),     - Mail-11 and     - PC LAN messaging



RARE WG-MSG Task Force 88                                       [Page 3]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    Three major European communities are referenced:

    - Commercial service providers     - R&D community     - Commercial organisations using messaging services.

   The report states the following facts:

    - The resources, human or financial, to operate multiple wide       area messaging services connecting together independent       organisations are high. As such it is desirable to try and       keep to a minimum the number of such services. This statement       is true for the R&D community but is also highly likely to be       valid for the general European industry.

    - There are two publicly available technological standards       that can be used by open communities, such as the R&D       community and public service providers: the X.400(1984 and       1988) recommendations and the Internet RFC 822 / MIME / PEM       standards.

    - There is an established very large global user base of       Internet RFC 822 and X.400(1984) messaging services. Both       services have their own momentum within different parts of       the user community, both are still developing and growing       fast.

   The report concludes that X.400(1988) will be the preferred protocol    for inter organizational connection for European industry and    government and parts of the European R&D community.  RFC 822 / MIME /    PEM will be the preferred protocol suite for inter-organisational    connection for the Internet community and, as products are already    widely available, it is the preferred protocol for parts of the    European R&D community.

   The goal of European pervasive messaging - incorporating Industry,    Government and Academia - would be best accommodated and reached by    the establishment of a single messaging service.  However taking the    above into account, this is not feasible, as X.400(84 and 88) and RFC    822( and MIME) based services will be around for a long time to come.    To increase the functionality of Wide Area E-mail services there is a    clear necessity to:

    - migrate RFC 822 services to a RFC 822 / MIME / PEM service.       A MIME based service offers more functionality to the user       than a plain RFC 822 service.

    - migrate existing X.400 services to a X.400(1988) service.



RARE WG-MSG Task Force 88                                       [Page 4]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       Due to the lack of scalability of the X.400(1984) service in       terms of extra functionality, it will become increasingly       difficult to meet the needs of research users of existing       X.400(1984) services unless an X.400(1988) service is put       into place.

    - provide a transparent gateway between X.400(1988) and RFC       822/MIME/PEM. For the European R&D community it is essential       to have a transparent gateway between the X.400(1988) service       and the RFC 822 / MIME / PEM service, thus ensuring       connectivity between these two services with a maximum       functionality.

   Such a gateway is technically feasible and it is an essential part of    an unified E-mail service. Without such a standardised gateway the    overall E-mail service would deteriorate.

   The lack of open standards for the PC LAN messaging systems    discourages their use as 'backbone' messaging technologies within    open communities. However the products that these systems deliver to    end users ensures that their already large share of the messaging    market will continue to exist for some time. Thus it is also    essential that strategies that allow these systems to be 'seamlessly'    integrated within the global messaging community are put in place.    Not least due to the indications that the main messaging vendors are    developing X.400(1988) and RFC 822/MIME gateways, a strategy to link    these systems together via X.400 and RFC 822 should be developed.

   The report concludes with a set of recommendations, the main one    being the establishment of a X.400(1988) European pilot messaging    service for the R&D community. This pilot should include the    establishment of a transparent gateway service between X.400(1988)    and RFC 822/MIME. The goal of a European pilot is to ensure the    successful deployment of a European wide operational X.400(1988)    service that is pervasive and meets the needs of users. By collecting    together the issues related to the establishment of a European    X.400(1988) service, this report acts as a focal point and stimulant    for discussion on this topic within the R&D community. In the report    a summary of the benefits and problems of each of the above messaging    technologies within the context of achieving a global messaging    service, of which the R&D community is one part, is presented.    Further the document identifies issues, strategies and    recommendations related to the migration and coexistence of these    technologies within the scope of mainly the European R&D community    but also in relation to other messaging communities. A cost / benefit    analysis on the establishment of a European wide pilot X.400(1988)    messaging service is also presented. Finally a reading list of    references related to this subject has been compiled.



RARE WG-MSG Task Force 88                                       [Page 5]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    The report does not include any recommendations on development and    deployment of RFC 822 / MIME / PEM related (pilot) services, as these    are outside of the scope of the Task Force. However, since the report    shows that both X.400(1988) and RFC 822 / MIME / PEM will be    developed and used within the European R&D community, such a pilot    should also be considered.

3.  Framework for the report

   With the belief that user demands for new messaging services such as    Multimedia and Secure Messaging would develop, the RARE community    (together with other communities; most notably the Internet    Engineering Task Force (IETF)) has over the preceding years    experimented in new messaging and related technologies.  Experiments    and pilots, have been performed in messaging services e.g., as    recommended by CCITT X.400(1988) and Directory Services based upon    the CCITT X.500(1988) recommendations.

   The results of such pilots and experiments indicate that it is now    opportune to commence a pilot X.400(1988) messaging service for the    European R&D community. The major goals of the pilot being, to

    - establish a large scale European wide pilot messaging       service based on X.400(1988).

    - collaborate with and facilitate the commencement of similar       pilot services within diverse communities; both R&D and non-       R&D (e.g., commercial ADMDs and PRMDs, etc.); both European       and non-European (e.g., North American , Asian, etc.).

    - encourage and assist the development and deployment of a       wide variety of commercial and public domain X.400(1988)       messaging products that meet the user's needs, for instance       X.400(1988) products such as User Agents (UAs), Message       Stores (MSs), Message Transfer Agents (MTAs) and gateways       between X.400(1988) services and other widespread messaging       services i.e., RFC 822, Mail-11 and proprietary.

    - prove that such a service and products efficiently meets the       existing and expected demands for new messaging services by       European R&D users. And as such determine the steps for a       European deployment of an operational X.400(1988) messaging       service.

    - determine the needed steps to facilitate migration for the       existing operational R&D X.400(1984) based messaging service,       as represented by the R&D MHS service (the former COSINE       MHS), RFC 822 / MIME / PEM based messaging services and the



RARE WG-MSG Task Force 88                                       [Page 6]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       HEPnet / SPAN Mail-11 based messaging service to an       operational X.400(1988) messaging service. It is self evident       that during such migrations, transition steps must be       included that allow a period of coexistence, at the highest       possible service level, between X.400(1988), X.400(1984), RFC       822 / MIME and HEPnet / SPAN Mail-11 services.

    - determine the needed steps that allow proprietary messaging       systems, that are widely deployed within the European R&D       community to be integrated at as high as possible service       level, by an X.400(1988) infrastructure.

   This report identifies the issues involved in such a pilot service.    It is not a concrete proposal for such a project but the report    discusses advantages and disadvantages, costs and enefits and    migration issues for deploying a X.400(1988) service. As such it is a    discussion and feasibility paper on the creation of a large scale    European wide pilot X.400(1988) messaging service for the European    R&D community.

4.  Present situation of European Messaging

4.1. Messaging services

   Electronic messaging within Europe can be viewed as a number of    messaging services communities. Three important communities comprise,

    - Commercial e-mail networks,     - Research e-mail networks and     - PC LAN messaging systems.

   Commercial e-mail networks are classified as either ADMDs or PRMDs.    ADMDs and PRMDs are operating in nearly every European country.

    - ADMD services (or public commercial e-mail services) are       provided by over 50 service providers which have       interconnected using the X.400(1984) protocols. The topology       between these ADMDs, although not yet 'mesh', can be stated       as progressing quite rapidly to this optimum goal. However       there is still a way to go before ADMDs provide full European       connectivity.

    - PRMDs (or private commercial e-mail service providers) have       interconnected to ADMDs and other PRMDs predominantly using       the X.400(1984) protocols but also with proprietary       protocols.





RARE WG-MSG Task Force 88                                       [Page 7]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    Research networks are providing messaging services in every European    country. These R&D service providers are operated as either ADMDs or    PRMDs and are using both X.400(1984) protocols and Internet RFC 822    protocols to connect to each other.

   Moreover, there are also large R&D communities (i.e., HEPnet and    SPAN) using proprietary protocols (i.e., DECnet Phase IV and Mail-11)    as their main messaging systems. The DECnet IV based communities are    now migrating to DECnet Phase V (OSI connectionless protocol stack),    which provides X.400(1988) (plus X.400(1984)) as a major messaging    system.  In general, all these services are totally interconnected.    As such it is a statement of fact that there exists within the    European R&D community, two parallel interconnected messaging    infrastructures based upon X.400(1984) and RFC 822. However    interconnections between the R&D messaging community and the majority    of the European commercial service providers use the X.400(1984)    protocols.

   It is also clear that the commercial world mostly makes inter-    organizational messaging interconnections using the X.400(1984)    protocols. And also that the commercial messaging world is not as    totally interconnected as the R&D messaging community.  Finally, for    a number of commercial and public organisations there is often a    mandatory requirement to use X.400 for messaging interconnections.

   The usage of PC LAN messaging systems is increasing very rapidly    within the academic and commercial communities. In general, PC LAN    messaging services within both communities do not use X.400(1984) or    RFC 822 messaging systems but systems based upon proprietary    protocols. The PC LAN messaging systems can be considered more as    'Islands of Messaging' that gateway to the commercial and R&D    messaging services by using X.400(1984) or RFC 822 gateways. PC LAN    messaging systems within commercial organisations connect to    commercial service providers also via proprietary protocols. The PC    LAN messaging services, although probably comprising the largest    number of users, are in general poorly integrated with the global    messaging service (The Dutch, UK and Italian academic communities    confirm that there appears to be many such 'Islands' of PC LAN    messaging systems within their networks.).

4.2. Requirements for messaging

   Experience with existing global e-mail services has proven that with    the increased use of messaging, there follows an awareness of extra    requirements for related services. These requirements can be    classified into 'User based Requirements' and 'Service Provider based    Requirements' to either support, or exploit, high quality messaging    services. These requirements are elaborated upon within this chapter.



RARE WG-MSG Task Force 88                                       [Page 8]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 4.2.1. User Oriented

   The only thing a user requires is an easy to use, well integrated,    user interface to electronic mail. Usually the user does not care    what protocol is used. However there are certain inherent    requirements to the functionality that can be identified as user    requirements. The main user requirements identified are:

   - Distribution Lists (DLs)

      A widely perceived omission from the X.400(1984) recommendations       was the lack of support of DLs. Distribution lists allow users to       enlist themselves onto electronic mail expander lists       (distribution lists). A message to such a distribution list will       automatically, and without significant delay, be sent on to anyone       whose electronic mail address is on that list. Such a list can be       a public list, that is meant for discussions on a specific       subject, much like a sort of "magazine". However the list can also       be a "closed" list, containing only a selected set of people who       need to communicate privately, e.g., a project-team.

   - Multinational language and Multimedia support

      European users have for many years been frustrated in their       inability to use their national character sets when communicating       using messaging systems. The problems within e-mail systems that       were causing this character set frustration are at their base the       same problem that would get in the way of Multimedia messaging       like:

         - lack of binary data support          - lack of standardised encoding schema's          - definition of multiple body-parts

      The enormous potential of Multimedia systems and services       (especially within the commercial community as evidenced by the       enormous press publicity and mega-mergers positioning companies to       exploit this technology but also within the government spheres       i.e., the U.S.A. Government's 'Information Superhighway'       initiative) has acted as a spur to make rapid progress in solving       the problems in this area.

   - White pages Directory Service

      A white pages directory service provides a unique but very basic       and important service; a way to store and find information about       people and resources that is analogous to a telephone service's       paper based directory i.e., White Pages. User's E-mail addresses



RARE WG-MSG Task Force 88                                       [Page 9]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       can be stored for subsequent retrieval by E-mail systems.

   - EDI

      EDI today is not extensively used within the academic environment.       However there is a distinct potential within the academic       community to reduce costs and improve services with EDI. Potential       EDI uses could be,

         - EDI between universities          - EDI between universities and government          - EDI between universities and lower level educational            institutions (e.g., student records)          - Commercial EDI using the Internet as an infrastructure.

      The significance of maintaining end to end integrity (especially       security aspects) of the EDI messages mandates that no gateways       should be used between originator and recipient.

   - Support of Security services

      E-mail as it is currently used is far from secure. To allow for       serious usage of E-mail security issues need to be addressed,       like:

         - integrity; making sure that the message is transferred            intact, without any changes or additions.          - encryption; making sure the message content is only            decipherable by the intended recipient.          - authentication; making sure that the originator and/or            recipient are authenticated.

4.2.2. Service provider viewpoint

   The task force believes the following points as being the most    significant service provider requirements:

   - Network Management

      This area is still very new, in terms of offering standardised       protocols, services and products for management. However a minimum       'goal' is to provide for central management functions that will       allow providers to offer a better quality of service.  There is       presently ongoing work within the IETF Working Group MADMAN to       define SNMP monitoring and managing of E-mail systems, gateways       and X.500 directory systems. A number of management areas that       need to be worked upon include: QOS, Service Level Agreements       (SLAs), Multiple system queue management, Accounting, Routing Co-



RARE WG-MSG Task Force 88                                      [Page 10]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       ordination and Message Tracing.

   - Support of MTA routing

      Dynamic routing from MTA to MTA, relieves the necessity to       maintain large routing tables, especially within a large PRMD, or       community of PRMDs (like the R&D MHS community).

   - Address mapping between RFC 822 and X.400

      The widespread use of X.500 or DNS for mapping, allows a reduction       of manpower for centrally co-ordinating globally consistent       X.400-to-RFC-822 mapping tables and distributes the responsibility       for updating the mapping rules. This should allow mapping rules to       change when needed and to be available immediately.

   - UA capabilities registration

      The use of the directory to register UA capabilities for       X.400(1988), X.400(1984) and RFC 822 / MIME / PEM systems is a       very desirable benefit for users in terms of speeding the       deployment of new messaging services (e.g., Multimedia Messaging).

4.3. Messaging capabilities

   Due to the problems of gatewaying within a multi-protocol messaging    environment, the great majority of R&D E-mail users are reduced to    using only InterPersonal Messaging (IPM) services based upon the    exchange of message body parts using CCITT character set IA5 (US    ASCII).

   Within the R&D community recent work to meet user requirements for    non ASCII messaging services - as documented above - has resulted in    enhancements to the messaging services based upon RFC 822 protocols.    The enhancements provide Multimedia support via the Multipurpose    Internet Mail Extensions (MIME) and the prospect in the very near    future of secure messaging via Privacy Enhanced Mail (PEM).    Deployment of the MIME enhanced RFC 822 based services, via    distribution of software and the setting up of the needed    organisational structures, has commenced. The PEM enhancements are in    a large scale pilot phase e.g., VALUE PASSWORD project.

   In the case of X.400(1984) the usage of non ASCII body parts is    mostly effected by bilateral agreement between recipient and    originator, through use of body part 14. In practice this restricts    the exchange of non ASCII body parts to those cases where the    recipient and the originator use the same bilateral agreement or else    the originator includes an ASCII message explaining the included



RARE WG-MSG Task Force 88                                      [Page 11]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    content type. Besides IPM there is a growing usage of EDI on top of    X.400(1984).

   With the above X.400(1984) deficiencies in mind, X.400(1988) has been    specified by the CCITT / ISO to meet new user demands.  X.400(1988)    provides support for various different body parts, enhanced security    features, international character set support capabilities and    support of X.500 Directory Services. Due to the technological    potential of these standards to satisfy user needs for new messaging    services, the R&D community has been experimenting and piloting    X.400(1988) and X.500(1988) services.  As there is a strong    dependency of X.400(1988) messaging upon X.500(1988) directory    services, the necessary precondition to supply these user demands is    a deployed and operational X.500(1988) directory service. Piloting    and deployment of the X.500(1988) directory service within the R&D    community has been successfully initiated and co-ordinated by the    COSINE and the VALUE PARADISE projects.

   Similarly, secure messaging has been addressed by the VALUE PASSWORD    project and the RARE and IETF communities. Work to solve problems    related to directory support of X.400(1988) messaging has been    pursued within the IETF and RARE. The relevant RARE and IETF work    groups (e.g., RARE WG-MSG, IETF MHS-DS, etc.) have also worked to    produce any needed enhancements to the base X.400(1988) and    X.500(1988) standards.  Last but not least it should not be    overlooked that X.400(1988), as compared to X.400(1984), provides a    comprehensive basis for gatewaying to and from RFC 822 / MIME / PEM    and PC LAN messaging services. To that respect the IETF has defined    standards for gatewaying Multimedia mail between RFC 822 / MIME / PEM    and X.400(1988). As RFC 822 / MIME / PEM is now being deployed on the    Internet, deployment of X.400(1988) services is needed to assure    multimedia and secure messaging connectivity for the European R&D    community.

5.  Possible solutions for providing globally pervasive messaging

   As can be now seen, a correlation of the present situation to the    requirements of the user, shows that the current messaging services    do not match the needs of users. To try to meet these needs a number    of developments within various messaging technology areas are    occurring. The following messaging technological areas, due to the    present installed user base within the R&D community, are considered    relevant:

      - PC LAN E-mail systems such as Lotus cc:Mail, Microsoft Mail         and Novell MHS       - RFC 822 / MIME / PEM E-mail services       - X.400(1988) messaging services



RARE WG-MSG Task Force 88                                      [Page 12]
 RFC 1616     X.400(88) for European Academics and Research      May 1994



   Ongoing developments within each of the above technological areas    provide new messaging options for the R&D community. The ability of    each technological area to provide solutions for user and service    provider requirements is summarised within this chapter.

5.1. PC LAN E-mail systems

   Currently the usage of PC LAN E-mail systems is mostly for internal    communication within an organisation. External connections, if    present at all, to public service providers or other organisations is    mostly through gateways to X.400(1984) or RFC 822. The use of a PC    LAN E-mail system in terms of an infrastructure for interconnecting    E-mail systems of different hues is not common within the Research    community.  Recent experience, from amongst others the Dutch Research    network - SURFnet - [14] and the Norwegian Directorate for Public    Management - Statskonsult - [18], has shown that a number of problems    (i.e., limited functionality, high operational management cost, etc.)    can be expected should these PC LAN E-mail systems be used as an E-    mail infrastructure. (The use of native X.400 protocols for PC LAN    E-mail systems would avoid the usage of gateways and would thus    alleviate many of these problems.) A summary of those problems and    some relevant issues follows:

   -  Interconnecting heterogeneous PC LAN messaging systems

      One very distinct benefit for E-mail users of all hues is the       potential to integrate heterogeneous PC LAN messaging systems with       a minimum loss of service (e.g., multimedia services) by       connecting them via X.400(1988) (or RFC 822/MIME/SMTP).       X.400(1988) is already being used, or under active development,       for connecting together PC LAN messaging systems in a number of       environments (e.g., Apple Macintoshes, DEC, Microsoft, Lotus,       etc.). This tendency to gateway PC LAN messaging systems via       X.400(1988) will increase and is one of the benefits that       X.400(1988) brings to global multiprotocol messaging.

   - Multimedia and binary data support

      The benefit of E-mail systems using these PC LAN systems is that       the user interfaces are usually well integrated in the users       standard working environment. Using a proprietary protocol these       systems allow not only text (ASCII) but also binary, word       processor, video, audio and other types of files to be       transported. To reap the benefits of this multimedia / binary data       transfer it would normally require that the same type of gateway       is used by sender and receiver. Transporting these same files to       another type of PC LAN E-mail system is not possible through the



RARE WG-MSG Task Force 88                                      [Page 13]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       current gateways without some information loss. In effect PC LAN       E-mail system's X.400 (or RFC 822) gateways from different vendors       perform acceptably only for text body parts.  True heterogeneous       multimedia PC LAN messaging needs gateways to X.400(1988)'s       service.

   - Application Programming Interfaces

      To help solve the problem of portability for Mail Enabled       Applications Microsoft, Lotus, Novell, XAPIA and X/OPEN have been       working on a number of standards for the Application Interface to       mail transport protocols (i.e., Mail Application Programming       Interface - MAPI, Vendor Independent Messaging - VIM, Common Mail       Calls - CMC). These efforts are structured independent of the       existing 'Wide-Area' or inter organisational E-mail protocols of       X.400(1984) and RFC 822. However the MAPI, VIM and CMC efforts,       due to their proposers (respectively Microsoft, Lotus and X/OPEN),       do look like they will provide the stimulant to various software       developers to develop more portable applications plus allow the       rich functionality of X.400(1988) to be accessed by these       applications thus reducing the need for gatewaying to X.400(1988).

   - Security

      As the PC LAN E-mail systems require gateways for connectivity,       they pose a problem with regard to encrypted messages.  Gatewaying       of secure messages is normally not possible. The gatewaying of       secure messages is a general problem of gatewaying from one mail       system to any other system and is not specific to PC LAN E-mail       systems.

   - Directory Services

      To date mostly proprietary directory services have been deployed       that do not match the needs of the users in terms of access       controls for data, distributed and decentralised across       organisations. X.500 based services promise solutions to such       needs. As a result various suppliers have announced support of       X.500 directory services for their E-mail products. However,       should these interfaces be delayed then support of an inter       organisational 'White Pages' services requires either,

      - directory information exchange products (i.e., directory         gateways) deployed between a proprietary system and an X.500         directory system





 RARE WG-MSG Task Force 88                                      [Page 14]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       - gateways between de-facto market based proprietary         standards, such as Retix Directory Exchange (DX) or         Soft*switch's Directory Synchronisation (DS), and X.500         protocols

      - duplicated directories i.e., one proprietary and one X.500         need to be operated.

   It should be stressed that gatewaying mechanisms and products are    often problematic due to the lack of an open standard on the    proprietary messaging system and or directory system. (As an aside it    is thus essential to establish an operational X.500 infrastructure,    including E-mail user interfaces that can transparently access this    Directory Service, as soon as possible.)

5.2. RFC 822, MIME and PEM services

   RFC 822 messaging services are widely deployed within the R&D    community. There is ongoing work to extend RFC 822 to meet user    requirements. Some of these extensions are elaborated upon within    this chapter.

   - Distribution lists

      RFC 822 allows for the usage of DLs. Management of DLs is not       (yet) standardised.

   - RFC 822 multimedia messaging via MIME

      With the arrival of MIME, the RFC 822 service has an additional       protocol standard that addresses Multimedia messaging very       comprehensively. In terms of user needs, MIME now allows messaging       body parts to comprise multinational character sets and binary       data. Multi-body part messages are also supported.  One of MIME's       real strengths, in terms of deployment within the existing RFC 822       service, is that it achieves its goals by overlaying its services       over the existing RFC 822 service and thus mandating no changes to       the in place RFC 822 infrastructure. This greatly simplifies the       MIME deployment.

   - RFC 822 secure messaging via PEM

      Just as MIME has brought multimedia messaging to RFC 822 services,       Privacy Enhanced Mail (PEM) is bringing secure messaging to RFC       822 services. PEM also has used the same approach as MIME to       deploy secure messaging within RFC 822 services; overlay PEM       services over the existing RFC 822 services without requiring       changes to the RFC 822 infrastructure. PEM brings confidentiality



RARE WG-MSG Task Force 88                                      [Page 15]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       and integrity of messages to RFC 822 users. However a number of       problems with PEM, and X.400(1988) as well, still need to be       solved before secure messaging can be considered to be an       operational service.  These problems are independent of the secure       messaging protocol (i.e., PEM or X.400(1988)) and deal mainly with       distribution of secret keys to the end users. There is very active       work going on within the IETF to solve these problems.

   - MIME and PEM

      There are still problems for messages that are simultaneously a       multimedia message, as per MIME, and a secure message, as per PEM.       A PEM encoded MIME message does not allow gatewaying to other       messaging environments and therefore does not allow any of the       features inherent within MIME to be exploited along the message       path. A MIME message that contains PEM encoded body parts can be       gatewayed but the integrity of the entire message is then not       guaranteed. This is a real deficiency of both existing approaches       as it is essential that users are able to simultaneously use       multimedia and secure messaging. However, once again, the IETF is       working very hard on solving these problems and solutions can be       expected, although the solution of the gatewaying of PEM messages       to other E-mail systems is still unclear.

   - Dynamic and distributed messaging routing via the Domain Name      System (DNS)

      RFC 822 messaging benefits greatly by having a dynamic and       distributed mechanism to assist in message routing i.e., Domain       Name System (DNS). With the support of the DNS, RFC 822 MTAs are       able to directly route to other RFC 822 MTAs and thus deliver       messages with a minimum of delay. In practice mail often still       traverses multiple RFC 822 MTAs for a number of reasons e.g., Mail       Hubs provided for users who turn their machine off when they go       home, Firewall Hubs for security reasons, etc. However it is       commonly accepted that between RFC 822 mail hubs the delivery of       messages is very fast. Typically resolution of routing decisions       occurs in less than one minute and very often within seconds. In       general the DNS service is a very valuable service that functions       well in practice.

   - Support for Character sets

      Together with the MIME specification for content types, an       extension for RFC 822 headers was defined that allows for usage of       multiple character sets in names, subject etc. in RFC 822 headers       [9]. This allows (European) users to use their preferred character       set to support their language not only in the contents of a



RARE WG-MSG Task Force 88                                      [Page 16]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       message but also in the headers.

   - MIME capable gateways

      It is clear that to provide a seamless service to all users       regardless of whether they are using RFC 822 or X.400 services, a       widely available set of well run and standardised RFC 822 to X.400       gateways must be in place. For InterPersonal Messaging (IPM) based       on US ASCII there are already a large number of such standardised       (i.e., X.400-to-RFC 822) gateways deployed. To ensure seamless       gatewaying between MIME and X.400 multimedia users, these existing       text based gateways must be either upgraded to or replaced with       multimedia messaging gateways. A number of proposed Internet       standards to solve these problems, for both X.400(1984) and       X.400(1988) and generated within the MIMEMHS work group of the       IETF, have been completed [4].

   - Access to fax, teletex, telex or physical delivery

      For the moment, there is no standardised way for RFC 822 users to       access gateways to the above services except by indirect access to       X.400(1988) systems (i.e., concatenated gateways of RFC 822 to       X.400(1988) and then onwards to the appropriate X.400(1988) Access       Unit). Although even this indirect method would require some       further work on standardising mappings between RFC 822 addresses       and X.400(1992)'s X.121 addresses. As well some experiments within       the RFC 822 world are occurring on routing fax messages.

   - Operational support

      Generally, RFC 822 messaging services are delivered on a 'best       effort' basis and thus service level agreements requesting       stringent response times to operational problems or guaranteed       delivery times for messages are difficult to agree. This phenomena       might be a result of the distribution and delegation of authority       to organisations updating the RFC 822 MTA's routing mechanism       i.e., DNS. As a result it makes it hard to reach a 'one stop       shopping' agreement for RFC 822 messaging services.

   - Notifications

      The RFC 822 service provides a minimum amount of base protocol       support for messaging users. It could be argued that the RFC 822       protocol is simplified by this choice and thus software that       implements the standard need be smaller in size and easier to       build. However some features e.g., delivery & receipt       notifications and UA capabilities registration, would be commonly       accepted as being desirable from a user standpoint and thus

 RARE WG-MSG Task Force 88                                      [Page 17]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       desirable extensions to RFC 822. Some operational problems       relating to reliability could be minimised by technology that has       a standardised support for positive and negative notifications of       messages. RFC 822, as compared to X.400, technology does not yet       support positive notifications (although there is work starting       within the IETF to extend RFC 822 to support delivery       notifications). However within RFC 821 transport system (i.e.,       SMTP) there are standardised negative notifications that work       well.  Alternatively X.400 technology, deployed over TCP/IP (using       STD 35, RFC 1006), may help to address the lack of adequate       service quality - notification support - when using E-mail within       the Internet.

   - Portability of RFC 822 products

      There are only a few mailbox formats in general use by RFC 822       software, one being the 'bin/mail' format and the other 'MH'       format.  This 'standard' mailbox format is a definite benefit for       RFC 822 users as it allows them to change RFC 822 UAs (e.g.,       upgrading to MIME RFC 822 UAs) whilst not compromising or       converting their existing archived mail, which may comprise 1000s       of archived messages.

   - System support for RFC 822 products

      Normally, RFC 822 MTAs and UAs come pre-installed on UNIX       workstations. As a result, users are spared the effort of       installing RFC 822 MTA software. If for some reason, a user or       mail administrator should wish to install a different MTA or UA to       the pre-installed system, there exists a large number of easily       available (i.e., via widespread distribution amongst many FTP and       other information servers) public domain RFC 822 MTAs and UAs.

      Both of the above points encourages the spread and eases the       installation of software for the RFC 822 messaging service and in       many ways explains the size and importance of the installed base       of RFC 822 systems. To illustrate the extent of RFC 822 / MIME       products, a non-comprehensive list of available MIME enhanced RFC       822 products follows; ELM 2.4, MH 6.8, Sun Mailtool, HP Mpower       Desktop, Lotus cc:Mail (unconfirmed), Zcode Zmail, Frontier       Super-TCP for Windows, PMDF (VAX VMS), Pine, C-Client (library       routines), Metamail (viewer only), Andrew-MIME gateway.

   - UA capability registration

      The IETF MHS-DS working group has defined how X.400 and RFC 822       User Agent capabilities can be stored in X.500 directory services.       This work is still ongoing.



RARE WG-MSG Task Force 88                                      [Page 18]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 5.3. X.400 - 1984 and 1988

   X.400(1988) substantially upgrades and enhances the X.400(1984)    standards. A number of new functions have been incorporated within    X.400(1988). A description of the most important features of X.400 -    1984 and 1988 - follows.

   - Notifications

      X.400(1984) provides four notifications - positive and negative       delivery notifications and positive and negative receipt       notifications. These notifications allow users to ensure       successful message delivery or that the message was read. The       delivery notifications are also used by service operators in their       fault escalation procedures.

   - Binary Data Transfer

      X.400(1984) allows binary data transfer to be transported without       the necessity of character encoding. The ability to transfer files       of whatever type is a valuable end user service.  As well the lack       of any necessary character encoding allows users to utilise the       received data without needing any character decoding software.

   - Multiple Body Parts

      The ability to send multiple body parts within one message gives       the user the ability to send multiple logical components within       one message. This is a natural mechanism for users as it mirrors       the real life situation of being able to send within one message,       a letter, a word processor file, a spreadsheet file, etc.

   - Feature rich messaging model

      The features of X.400 are very rich. This provides benefits for       users as vendors are able to provide applications that can utilise       these extensive features in an interoperable manner due to the       standardisation of the features within X.400.

   - Clear messaging model

      X.400(1984), as one of its most wide reaching achievements, has       popularised within the market a consistent and clear model to       describe message handling systems. The decomposition of a message       handling system into UAs, MSs, MTAs, MTS - ADMDs and PRMDs and       Access Units / Gateways has proved to be an extremely useful tool       for users and vendors to understand and communicate their       messaging needs or solutions.



RARE WG-MSG Task Force 88                                      [Page 19]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    - Multiple lower layer networks

      X.400 has embraced the concept that there are different technology       lower layer networks. This concept even allows multiple logical       networks of the same technology to be supported. X.400 allows the       messaging service to fully function even though the underlying       network is varying. In the real world of a non-uniform network       layer this is an extremely powerful capability.

   The list of major X.400(1988) extensions to X.400(1984) follows:

   - Distribution Lists (DLs)

      A powerful mechanism for arbitrarily nested Distribution Lists       including the ability for DL owners to control access to their       lists and to control the destination of non delivery reports.  The       current endemic use of DLs in the R&D community makes this a       fundamental requirement for any service. X.400(1988) uses X.500 to       provide a standardised support for DLs, although there have been       some needed standardised enhancements relating to the CCITT       defined DLs by the IETF MHS-DS work group. The provision of       powerful nesting capabilities plus management mechanisms for DL       owners within X.400(1988) DLs are features providing attractive       benefits for users and DL managers.  There is already 'running       code', via the COSINE Explode project which is implementing the       MHS-DS based enhancements. The project builds upon experience       gained within a number of networks e.g., JNT and provides:

         - implementation of MHS-DS enhancements related to the            X.400(1988) DLs          - archiving of messages received by a DL.          - access by users to the DL archive via e-mail.          - subscription to a DL by users via e-mail.

   - Message Store (MS)

      The Message Store provides a server for remote UAs on workstations       and PCs enabling messages to be held for their recipient, solving       the problems of non-continuous availability of such UAs. The       message store allows mobile workers, small offices and local       schools to become active messaging users in a cost effective       manner. The message store provides powerful selection mechanisms       allowing the user to select messages to be transferred between the       store and the workstation. This facility is not catered for       adequately by the P3 protocol of X.400(1984) and provides a major       incentive for transition.





RARE WG-MSG Task Force 88                                      [Page 20]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    - X.500 Directory names

      Support for use of Directory Names in MHS will allow a transition       from use of O/R addresses to Directory Names when X.500       Directories become widespread, thus removing the need for users to       know about MHS topological addressing components.

      The ability for X.400(1988) messages to contain directory names       instead of the O/R addresses is a powerful feature for users as it       frees them of the necessity to insert O/R addresses containing       routing information but allows them to insert the more natural       directory names. However, the management of the large amounts of       distributed data contained within the directory is problematic in       that it involves a number of organisational issues and not just       software issues. A number of X.400(1988) UAs which allow users to       insert directory names instead of O/R addresses have already been       developed.

   - Support for EDI

      Through the definition of Pedi, as defined in X.435, X.400(1988)       offers integrated support for EDI messaging. The CEC TEDIS program       has mandated X.400 as the main carrier for EDI, and standardised       how EDI transactions are inserted into X.400 messages (i.e., Pedi       and P2). This provides a strong incentive to provide native       X.400(1988) services to users and applications thus encouraging       commercial EDI traffic to migrate to X.400(1988).

   - Secure Messaging

      The provision of secure messaging services including       authentication, confidentiality, integrity and non-repudiation as       well as secure access between MHS components are important       benefits for the R&D community. The base standards are adequate       for security, however organisational and software issues need       still to be solved. Organisational issues of globally scaling the       distribution of secret keys is still unsolved. Software issues of       how end users will be able to comfortably and securely input       secret keys of length 512 -> 1024 bits into security software need       to be solved.

   - Multimedia

      The definition of a number of additional body parts plus the       ability to define new body parts (e.g., Word Processor formats,       Excel documents, etc.) provides the basis for multimedia services       over X.400(1988). As well, the newly defined General Text body       part supports multinational character sets (except for ISO 10646)



RARE WG-MSG Task Force 88                                      [Page 21]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       without the need for transmission encoding. However, unlike MIME,       X.400(1988) is only specifying a standard for multimedia       messaging. To achieve multimedia document exchange, there is a       further text exchange standard such as ODIF, Hytime, etc., needed.

   - Character set support for extended addressing

      A highly desirable potential benefit for European R&D users is       provided by the extended character set support(i.e., T.61) within       addresses. Nearly all European languages, except for Greek and       Cyrillic, are supported by the T.61 teletex encoding. Further       extensions to X.400 for support of extended character sets has       been defined by the RARE WG on character sets and RARE WG on       messaging [15].

   - Physical Delivery Services

      This standardised method for a message to be delivered on a       physical medium, such as paper, through the normal postal service       is useful when trying to reach a very wide number of (non-       electronically reachable) recipients. In effect this service       provides an ability to 'go the last mile' and communicate with       users previously not easily reachable e.g., farmers, etc.

   - General Extension Mechanism

      One of the major assets of X.400(1988) is the extension mechanism.       This is used to carry most of the extensions defined in these       standards, but its principal benefit will be in reducing the       trauma of transitions to future versions of the standards.

      Provided that implementations of the X.400(1988) standards do not       try to place restrictions on the values that may be present, any       future extension will be relayed by these implementations when the       extension is not critical, thus providing a painless migration to       new versions (1992 and beyond) of the standards.

   - UA Capability Registration

      With the extra functionality available to X.400(1988 and       especially 1992) UAs (i.e., extra non-IA5 body parts, secure       messaging, etc.) it is expected that the demand to register UA       capabilities will increase. In that respect X.400(1988)'s ability       to query X.500, where such capabilities would be stored, is a       significant potential benefit for users.





 RARE WG-MSG Task Force 88                                      [Page 22]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    - X.500 support for MTA routing

      The piloting of X.500 to support MTA routing within the R&D       community has already commenced, on a small experimental scale,       via the Longbud project co-ordinated by the IETF MHS-DS work       group. Some concrete benefits promised by X.500 based routing are:

      - routing based upon content types, security, transport stacks         and other criteria allow optimum routing paths to a         destination MTA to be chosen. (There is presently no such         similar capability within the DNS).

      - allowing the routing information to be inserted and modified         in a distributed manner reduces (if not eliminates) the         necessity of central distribution of static routing tables.         The consequent reduction in manpower to co-ordinate MTA         routing plus the increase in scalability of the service         allows a truly global messaging service to be put in place.

6.  Migration to X.400(1988)

   What is clear from the previous chapters is that;

      - The resources, human or financial, to operate multiple wide         area messaging services connecting together independent         organisations are high. As such it is desirable to try and         keep to a minimum the number of such services. This statement         is true for the R&D community but is also highly likely to be         valid for the general European industry.

      - There are two publicly available technological standards         that can be used by open communities, such as the R&D         community and public service providers: the X.400(1984 and         1988) recommendations and the Internet RFC 822 / MIME / PEM         standards.

      - There is an established very large global user base of         Internet RFC 822 and X.400(1984) messaging services. Both         services have their own momentum within different parts of         the user community, both are still developing and growing         fast.

   From the above discussion, it is clear that the infrastructure    services that have to be supported within these open communities, and    especially within the R&D community, are RFC 822 / MIME / PEM,    X.400(1984) and X.400(1988). X.400(1988) will be the preferred    protocol for inter-organisational connection for European industry    and government and parts of the European R&D community. RFC 822 /



RARE WG-MSG Task Force 88                                      [Page 23]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    MIME / PEM will be the preferred protocol suite for inter-    organisational connection for the Internet community and, as products    are already widely available, it is the preferred protocol for parts    of the European R&D community.

   The goal of European pervasive messaging - incorporating Industry,    Government and Academia - would be best accommodated and reached by    the establishment of a single messaging service.  However taking the    above into account, this is not feasible, as X.400 and RFC 822 based    services will be around for a long time to come. To increase the    functionality of Wide Area E-mail services there is a clear necessity    to:

      - migrate RFC 822 services to a RFC 822 / MIME / PEM service.         A MIME based service offers more functionality to the user         than a plain RFC 822 service.

      - migrate existing X.400 services to a X.400(1988) service.         Due to the lack of scalability of the X.400(1984) service in         terms of extra functionality, it will become increasingly         difficult to meet the needs of research users of existing         X.400(1984) services unless an X.400(1988) service is put         into place.

      - provide a transparent gateway between X.400(1988) and RFC         822/MIME/PEM. For the European R&D community it is essential         to have a transparent gateway between the X.400(1988) service         and the RFC 822 / MIME / PEM service, thus ensuring         connectivity between these two services with a maximum         functionality.     Such a gateway is technically feasible and it is an essential part of    an unified E-mail service. Without such a standardised gateway the    overall E-mail service would deteriorate.

   The lack of open standards for the PC LAN messaging systems    discourages their use as 'backbone' messaging technologies within    open communities. However the products that these systems deliver to    end users ensures that their already large share of the messaging    market will continue to exist for some time. Thus it is also    essential that strategies that allow these systems to be 'seamlessly'    integrated within the global messaging community are put in place.    Not least due to the indications that the main messaging vendors are    developing X.400(1988) and RFC 822/MIME gateways, a strategy to link    these systems together via X.400(1988) and RFC 822/MIME should be    developed.





RARE WG-MSG Task Force 88                                      [Page 24]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    To make migration to a X.400(1988) service feasible, extensive    migration and coexistence options for various non-X.400(1988) users    have to be developed. Main issue in each migration strategy remains    the co-operation of the users. The migration needs to be user-driven,    i.e., the users need to be convinced of the added functionality    (versus the cost) of migrating towards X.400(1988). A detailed    summary of the different issues and possible problems involved in the    transition to a X.400(1988) based messaging service, with respect to    what are commonly accepted as the four most important messaging    services: RFC 822, MIME and PEM; X.400(1984); MAIL-11 and PC LAN    messaging systems are presented in this chapter.

6.1. PC LAN E-mail systems

   To provide coexistence and migration the usage of gateways is    unavoidable. The quality of these gateways, with regard to:

      - Transparency (gatewaying multimedia messages, transparent         addressing)       - Manageability       - Reliability

   has to be improved. Ultimately through usage of APIs like MAPI and    CMC, the users interface hopefully will become independent of the    mail protocol that is used. It will then be expected to be possible    to let the user retain his preferred mail user interface, while the    protocol used migrates to X.400(1988).

   Via the use of these APIs it may be possible to access the full    features of X.400(1988) while retaining a proprietary PC LAN UAs.    This way a PC LAN can be easily connected to a X.400(1988) backbone.    This usage of APIs to ease migration for end users should be    encouraged.

   The migration of PC LAN E-mail systems will likely be driven by the    commercial vendors of mail enabled applications, such as UAs, Work    Group Systems, Task Flow Systems plus X.400(1988) MTAs and gateways    able to serve these applications via these new APIs.

6.2. RFC 822, MIME and PEM services

   A migration from RFC 822 / MIME and PEM services to X.400(1988) needs    to be formulated for those management domains that wish to effect    this change. As well a long term transition and coexistence phase    needs to be accommodated due to the existing base of RFC 822 users.    An understanding of the issues involved in migrating from RFC 822 to    X.400(1988) messaging services is essential before any rational    decisions on migration can occur.  Certainly one, if not the main,



RARE WG-MSG Task Force 88                                      [Page 25]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    issue in such a migration is that the migration must allow a    transition period where maximum functionality between both services    exists. Any migration must be aware that RFC 822 messaging services    are a 'moving target'.

    - Ease of transition as perceived by an RFC 822 user mandates       that the user's existing mail folders are converted into the       new mail product's folder system flawlessly.

    - The RFC 822's user's e-mail address should remain the same       even after a migration. (i.e., the user keeps the same address       that has two different notation forms: X.400 and RFC 822).

    - Users contemplating a migration will be stimulated to do so       if they experience no loss of service as regards MIME and       X.400(1988) gatewaying; are still able to insert RFC 822       style addresses into the X.400(1988) UA and are provided with       high performance X.400-to-RFC 822 gateways.

    - The added connectivity provided by X.400(1984 or 1988)       gateways to fax, telex, post etc. plus additional X.400 users       that the user is able to reach easily (whilst not losing       connectivity to RFC 822 addresses) plus the additional       functionality of X.400(1988) possible when communicating with       X.400(1988) users will also act as a stimulant to a       migration.

    - The functionality provided by RFC 822 / MIME products will       be the yardstick that an RFC 822 user compares an offered       X.400(1988) product with. As such X.400(1988) products must       provide some basic and important functions like: Character       Set support via GeneralText; Multimedia capability via       Extended Body Parts; low message delays within the seconds       time scales and ease of configuration of products. At present       there is no RFC 822 equivalent to X.400 delivery and receipt       notifications and as such these functions are seen as extra       functionality by the user.

    - A follow on to the extra functionality point above is that       present RFC 822 users, most likely commercial users, that       want to be able to use EDI or other mail enabled applications       that need security, message audits and positive confirmations       will be encouraged to migrate to X.400(1988). A decision to       use X.400(1988) in this case would be especially attractive       for those commercial RFC 822 users that are already operating       multiple lower layer networks. As X.400(1988) accommodates       multiple different network layers easily, the cost to migrate       could be considered quite small.



RARE WG-MSG Task Force 88                                      [Page 26]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 6.3. X.400(1984) services

   A number of problems can be identified in a migration from    X.400(1984) to X.400(1988). They are summarised as,

    - OSI supporting layers are mandatory in the ISO10021 MOTIS       standard, while the support of the complete OSI stack (normal       mode ) is optional in the otherwise equivalent CCITT       X.400(1988) specifications. It is thus recommended that the       migration from X.400(1984) should be straight to ISO 10021       i.e., straight to use of the full OSI stack with normal mode       RTS.

    - There is a negative impact on quality of service caused by       implementation decisions related to the 'General Extension       Mechanism'. To overcome this negative impact no minimal       X.400(1988) MTAs, which relay the syntax but understand none       of the semantics of extensions, should be used.

    - All X.400(1988) MTAs should generate reports containing the       extensions that are present in the original message and route       such reports through the DL expansion hierarchy where       appropriate.

    - Choice of standards to be used within mixed X.400(1984 and       1988) management domains needs to accommodate in one option       the danger of undetectable routing loops from incorrectly       configured routing entries and in another option the problem       that systems that have fixed the routing loop problem may not       all be consistently implemented due to ambiguities within the       standards. The choice of which of these two options a       management domain uses internally has no impact on external       management domains.

    - DDA support is needed by X.400(1984) systems to address       X.400(1988) Common Name Attribute users [2].

    - Minimum loss of service quality mandates that downgrading of       X.400(1988) body parts to X.400(1984) bodyparts be done       according to the MIMEMHS specifications [4].

    - To enhance connectivity to both X.400(1984 and 1988)       management domains without degradation of X.400(1988)       service, management domain entry points that support both       X.400(1984 and 1988) are recommended.





 RARE WG-MSG Task Force 88                                      [Page 27]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

     - Ensuring that no X.400(1988) MTAs transit via X.400(1984)       MTAs. This allows no degradation of X.400(1988) service       quality [17].

   The consequence of the last point is that the existing European    Research X.400(1984) - formerly COSINE MHS - MTA RELAY backbone    should be one of the first MTA communities to migrate to X.400(1988).

6.4. Mail-11 services

   The Mail-11 (also known as DECnet mail) e-mail service is the major    e-mail service used within the High Energy Physics and Space Physics    Analysis Networks (i.e., HEPnet and SPAN) and is the native e-mail    service present on VMS operating systems. The Mail-11 service is    considered the most popular service by the large HEPnet / SPAN    community. Mail-11 provides also large and easy to use gateways to    other E-mail protocols, like X.400 (84), RFC 822 (SMTP over TCP/IP,    DECnet and X.25, BSMTP over NJE), and PC LAN E-mail services.

   Jointly with the "old style" Mail-11 UA, the DECnet Phase V (OSI    CLNS) service provides the native capability to run X.400 (88) and    X.400(1984) services. There is thus the potential for X.400 (88)    services to become available as soon as the HEPnet / SPAN community    migrates to DECnet Phase V. However the availability of VMS based UAs    for the X.400(1988) service is still very limited and is thus forcing    users to continue to stay with their Mail-11 UA (and thus the Mail-11    service).

   Users in HEPnet / SPAN are demanding enhancements to their mail    services to support multimedia and delivery / read receipt services.    This is a strong driving factor for good X.400(1988) UAs to become    available soon to allow users to properly use the available    X.400(1988) service of DECnet Phase V.

7.  Benefits of migrating to X.400(1988) and the involved costs

   The actual as compared to the potential benefits of migrating from    one's existing mail system to a new mail protocol is very dependent    on good products, good organisation of the migration and a degree of    commitment that the transition is worth the cost. Quantifiable and    accurate cost / benefit ratios for such a migration are not possible    within the decentralised European R&D environment and as such are not    generated.

   We have in this chapter listed the benefits that such a migration to    X.400(1988) achieves. We have also given an indication of the    relative costs of such a migration. Provided that there are good    products, and taken in conjunction with the recommendations of



RARE WG-MSG Task Force 88                                      [Page 28]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    Chapter 8 and Appendices A and B, the task force is confident that    these potential benefits will translate into actual benefits and be    worth the costs incurred.

*Benefits*

   Below is a list of non-technically oriented benefits and the features    of X.400(1988) that enable these benefits to occur. The benefit of,

    - efficient and innovative communication within Europe is       assisted by establishing an X.400(1988) messaging service       that integrates European industry, government and academia;

    - an increase in business efficiency by the use of EDI (for       example automatic processing of business forms, exchange of       business contracts, etc.) is enhanced by the security aspects       of X.400(1988) i.e., non-repudiation, authentication,       confidentiality, integrity plus secure access between MHS       components.

    - allowing European users to communicate in their native       European languages is brought about by the GeneralText body       part of X.400(1988).

    - remote users and Small and Medium size Enterprises(SME)       using e-mail for electronic commerce is encouraged by       reducing the entry level costs for use of e-mail. An SME's       use of Remote UAs in conjunction with a service provider's MS       -instead of purchasing their own MTA - is accommodated by       X.400(1988).

    - providing global messaging for all e-mail users, but       recognising the existing market realities of heterogeneous e-       mail systems, would be enhanced by the establishment of       gateways to X.400(1988).

    - being able to recover costs by charging and accounting for       messaging services back to users - this is especially       important for commercial service providers - is brought about       by the message auditing capabilities of X.400(1988).

    - communication with users that have no access to E-mail (for       example if such users are defined within Distribution Lists)       is enhanced by X.400(1988)'s support for gateways to physical       delivery, fax, telex, teletex, etc.





 RARE WG-MSG Task Force 88                                      [Page 29]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

     - building upon the existing X.400(1984) infrastructure (i.e.,       reduction of establishment costs) is brought about by       migrating the X.400(1984) infrastructure to X.400(1988).

    - a reduction in manpower (and thus costs) to manage a global       messaging service is brought about by the messaging service's       ability to utilise the global distributed directory for       management information.

    - the messaging infrastructure to meet new user requirements       is enhanced by the support for General Extensible Mechanism.

    - making E-mail more user friendly is brought about by a       messaging service that allows the use of the more natural       directory names in E-mail addresses.

    - increased effectiveness of messaging by the use of DLs is       brought about by X.400(1988)'s support of powerful nesting       capabilities and management for DLs.

    - an increase in global message delivery performance and       reliability is enhanced by the ability of X.400(1988) to use       X.500 for MTA routing.

    - more messages being successfully delivered to mobile or       transient users is enhanced by the provision of the Message       Store.

    - multimedia use is enhanced by the ability to define new body       parts and to support multiple types of binary data such as       audio and video.

    - establishing optimum and seamless conversion of messages       based upon the capabilities of a user is brought about by the       ability of X.400(1988) to act upon UA capabilities.

*Costs*

   The generic costs to establish an X.400(1988) pilot service can be    broken down into:

       - a cost per backbone of RELAY MTAs (as used by the European          research community - the former Cosine MHS service),        - a cost per service provider,        - a cost per organisation,        - a cost per user and        - a cost per user MTA for migrating to X.400(1988).



 RARE WG-MSG Task Force 88                                      [Page 30]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    To bring about the benefits, mentioned above, certain costs will be    incurred and they are summarised below:

   - Cost per backbone of RELAY MTAs (as used by the European      research community - the former Cosine MHS service)

         - The equipment costs of migrating backbone RELAY MTAs.

         - The establishment of some sort of organisational /            project group to oversee a backbone RELAY MTA pilot.

      As most of the RELAY MTAs are already X.400(1988) capable, there       is already a MHS Co-ordination service in place that could be used       for this function and the number of backbone RELAY MTAs is less       than 100 in number the cost for migrating the RELAY MTA backbone       is considered relatively low.

   - Cost per service provider

         - If the RELAY MTA backbone (formerly Cosine MHS) is            migrated towards X.400(1988), then the remaining cost            for a service provider for migrating the infrastructure            towards X.400(1988) is relatively low.

         - The operational costs for organisational issues, for            example dealing with OID registrations, is low if            national R&D service providers act as a clearinghouse            for their own national R&D institutions e.g.,            Universities.

   - Cost per organisation, end user and MTA

         - The operational costs of migrating end users and their            MTAs in management domains to X.400(1988) are higher            than the costs involved with migrating the            infrastructure. This is due to the order of at least 10            to 100 times more MTAs, as compared to the service            providers, that would be involved with a migration to            X.400(1988). As the infrastructure needs to migrate            first, the costs for the end user MTAs can be reduced            by profiting from the migration experience of the            service providers.

         - The education and training costs for users and system            managers are significant, due to the amount of end            users and end user MTAs. Any marginal cost savings per            user which can be made, e.g., by deployment of automated            tools, should be considered due to the large overall



RARE WG-MSG Task Force 88                                      [Page 31]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

            savings that accrue.

         - The costs of any potential disruption of the end user's            messaging service are high - due to the huge numbers of            end users involved - and as such only a very well            managed, phased and planned migration should be            considered.

   - Software costs

         - The costs for software development are outside the            scope of this report. However it is clear that cost            needs to be incurred in order to provide software that            is easy to install and use. As a result of the work of            the task force a list of possibly needed components and            likely changes to existing components can be proposed,

                Modifications, but not new developments, to                   software for:

                     - X.400(1988) MTAs, X.400(1988) UAs, DSAs,                        DUAs and MSs.

                New software developments for:

                     - MIME to MHS Gateways, X.400(1988) network                        management, mailbox conversion, PC LAN                        directory synchronisation, PC LAN gateways                        and UA capability registration.

         - The distribution costs for any new software (for the            European R&D community) are low if usual academic            distribution methods - FTP servers, E-mail Based            servers, Gopher, World Wide Web and Archie - are used.

*Summary*

   Migration towards a X.400(1988) service needs to evolve from the    inside (the messaging backbone) outward (to the end user MTAs and end    users themselves). Due to the numbers involved both the costs and the    benefits associated with the migration increase as the migration    evolves towards the end users.

   The benefits of migrating to a X.400(1988) service are a feature rich    well defined open standard with high functionality , scalability, use    of directory, multimedia and secure messaging capability. The costs    for migrating a RELAY MTA backbone can be considered relatively low    whilst the migration of end user MTAs and the migration of the end



RARE WG-MSG Task Force 88                                      [Page 32]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

    users themselves are relatively high. These costs should of course be    balanced against the cost of a disrupted service that one might get    if no migration occurs at all and the current service (e.g.,    X.400(1984)) reaches the limits of its scalability and/or    functionality.

   It is important to realise that if end users themselves do not    experience direct feedback of the benefits from X.400(1988), this may    make the organisational motivation needed to effect such a migration    difficult to achieve. In effect, the establishment of a pilot    X.400(1988) service is and should be driven by the requirements of    end users and thus achieving end user benefits - as listed above -    must be given a higher priority within a X.400(1988) service than    solely the extra service provider benefits.

8.  Main Recommendations

   The RARE WG-MSG Task Force on 'The Establishment of an X.400(1988)    Pan European Pilot Messaging Service' has identified a number of high    level recommendations for establishing such a     service. The main high level recommendations are listed within this    chapter. A more detailed elaboration of these main recommendations is    given in Appendix A. Appendix A is provided for policy makers wishing    more background on the main recommendations. As well, a list of very    detailed guidelines, plus some issues requiring further    investigation, is given in Appendix B. Appendix B will be especially    useful for personnel seeking detailed technical guidelines which are    consistent with the main high level recommendations.

*Recommendations*

    - Establish a X.400(1988) pilot service encompassing European       Commercial, Government and Academic bodies. Such a pilot       service to be co-ordinated by using an industry forum where       all parties could meet. The use of an existing forum, where       user organisations are well represented, is desirable if       commercial end users organisation's requirements are to be       met. The forum should also be open to non-European       participants.

    - X.400(1988) end user services should be provided as well as       a X.400(1988) backbone RELAY MTA service within a X.400(1988)       pilot service. The end user services should be given a high       priority.

    - Help an already emerging market place in X.400(1988)       products to prosper by ensuring that a suitable supply of       high quality X.400(1988) public domain software is available.



RARE WG-MSG Task Force 88                                      [Page 33]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       The Internet has proven, that public domain software, free of       any commercial restrictions, is further rapidly developed, by       Small and Medium Size Enterprises (SMEs), into derivative       products suitable for the commercial market.

    - Any pilot service should be well co-ordinated and result       driven but utilise a distributed market oriented approach. It       is considered very difficult to organise and plan such a       pilot under the assumption of a single centrally funded body       i.e., driven from the 'top'. A more 'market driven' or       distributed organisation is considered feasible, and likely       to succeed, if all the market 'players' are fully involved       i.e., a 'bottom' up approach.

    - For the academic community - and ever more for the       commercial community - there is a business need to ensure near       total and 'perfect' integration with the existing and also       evolving RFC 822 based services.

    - For the academic community a rapid migration of the existing       X.400(1984) backbone RELAY MTAs, used within the European R&D       X.400(1984) service, - formerly the COSINE MHS service - is       considered urgent. This migration will provide a 'bootstrap'       path for academic organisations to internationally pilot       X.400(1988) services. Such end user piloting is not       considered feasible if X.400(1984) backbone RELAY MTAs are       used for an X.400(1988) service (see Reference [17] for       technical details).

   The report does not include any recommendations on development and    deployment of RFC 822 / MIME / PEM related (pilot) services, as these    are outside of the scope of the Task Force. However, since both    X.400(1988) and RFC 822 / MIME / PEM will be developed and used    within the European R&D community, such a pilot should also be    considered.

9.  Security Considerations

   Security issues are not discussed in this memo.











 RARE WG-MSG Task Force 88                                      [Page 34]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 10. Reading List and Bibliography

   This section contains a list of relevant reference documents that can    be used for further reading.

      [1]         Kille;, S., "Mapping between X.400(1988) / ISO 10021                   and RFC 822", RFC 1327/RTR 2, University College                   London, May 1992.

      [2]         Kille, S., "X.400 1988 to 1984 downgrading",                   RFC 1328/RTR 3, University College London, May 1992.

      [3]         Adie, C.,  "A Survey on Multimedia Projects, Products                   and Standards", RTR 5, Edinburgh University Computing                   Centre, January 1993.

      [4]         Alvestrand, H., and S. Thompson, "Equivalences between                   1988 X.400 and RFC 822 Message Bodies", RFC 1494,                   SINTEF DELAB, Soft*Switch Inc., August 1993.

      [5]         Alvestrand, H.,  Kille, S., Miles, R., Rose, M.,                   and S. Thompson, "Mapping between X.400 and RFC 822                   Message Bodies", RFC 1495, SINTEF DELAB, ISODE                   Consortium, Soft*Switch, Inc., Dover Beach                   Consulting, Inc., Soft*Switch, Inc., August 1993.

      [6]         Alvestrand, H., Romaguera,  J., and K. Jordan,                   "Rules for downgrading messages from X.400/88 to                   X.400/84 when MIME content-types are present in the                   messages", RFC 1496, SINTEF DELAB, NetConsult AG,                   Control Data Systems, Inc., August 1993.

      [7]         IETF MHS-DS Working Group, Works in Progress.

      [8]         Borenstein, N., and N. Freed, "MIME (Multipurpose                   Internet Mail Extensions) Part One: Mechanisms for                   Specifying and Describing the Format of Internet                   Message Bodies", RFC 1521, Bellcore, Innosoft,                   September 1993.

      [9]         Moore, K., "MIME (Multipurpose Internet Mail                   Extensions) Part Two: Message Header Extensions for                   Non-ASCII Text", RFC 1522, University of Tennessee,                   September 1993.







RARE WG-MSG Task Force 88                                      [Page 35]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       [10]        Kaliski, B., "Privacy Enhancement for Internet                   Electronic Mail: Part IV: Key Certification and                   Related Services", RFC 1424, RSA Laboratories,                   February 1993.

      [11]        Balenson, D., "Privacy Enhancement for Internet                   Electronic Mail: Part III: Algorithms, Modes, and                   Identifiers", RFC 1423, TIS, February 1993.

      [12]        Kent, S., "Privacy Enhancement for Internet                   Electronic Mail: Part II: Certificate Based Key                   Management", RFC 1422, BBN, February 1993.

      [13]        Linn, J., "Privacy Enhancement for Internet                   Electronic Mail: Part I: Message Encryption and                   Authentication Procedures", RFC 1421, IAB IRTF PSRG,                   IETF PEM WG, February 1993.

      [14]        Jurg, P., and E. Huizer, "The SURFnet electronic mail                   project", SURFnet, EH/PJ932307, July 1993.

      [15]        Alvestrand, H., "X.400 Use of Extended Character                   Sets", RFC 1502/RTR 7, SINTEF DELAB, August 1993.

      [16]        Manros, C.-U., "The X.400 Blue Book Companion", ISBN                   1 871802 00 8, Technology Appraisals Ltd, 1989.

      [17]        Houttuin, J., and J. Craigie, "Migrating from                   X.400(1984) to X.400(1988)", RFC 1615/RTR 9,                   RARE, JNT, May 1994.

      [18]        Nagelhus, I. et al., "Survey of E-mail systems with                   X.400 capability".

      [19]        "A White Paper on X.400(1988)", EMA Report.

      [20]        IAB, IESG, "The Internet Standards Process --                   Revision 2", RFC 1602, March 1994.













RARE WG-MSG Task Force 88                                      [Page 36]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 11. Terminology

      ADMD     Administration Management Domain       ASCII    American Standard Code for Information Exchange       ASN.1    Abstract Syntax Notation One       AU       Access Unit       CCITT    Comite Consultatif International de Telegraphique et                Telephonique       CEN      Comite Europeen de Normalisation       CENELEC  Comite Europeen de Normalisation Electrotechnique       CEPT     Conference Europeene des Postes et Telecommunications       CONS     Connection Oriented Network Service       COSINE   Co-operation for OSI networking in Europe       DL       Distribution List       DIS      Draft International Standard       EMA      Electronic Messaging Association       EN       European Norm       ENV      Draft EN, European functional standard       IEC      International Electrotechnical Commission       IETF     Internet Engineering Task Force [20]       IPM      Inter-Personal Message       IPMS     Inter-Personal Messaging Service       IPN      Inter-Personal Notification       ISO      International Organisation for Standardisation       JNT      Joint Network Team (UK)       JTC      Joint Technical Committee (ISO/IEC)       MD       Management Domain (either an ADMD or a PRMD)       MHS      Message Handling System       MHS-DS   Message Handling Systems use of Directory Service                Working Group from the IETF       MIME     Multi-purpose Internet Mail Extensions (extensions to                RFC 822) [6]       MOTIS    Message-Oriented Text Interchange Systems       MTA      Message Transfer Agent       MTL      Message Transfer Layer       MTS      Message Transfer System       NBS      National Bureau of Standardization       OSI      Open Systems Interconnection       PEM      Privacy Enhanced Mail [10]       PRMD     Private Management Domain       RARE     Reseaux Associes pour la Recherche Europeenne       RFC      Request For Comments (series of Internet publications)       RFC 822  RFC describing Internet Message format for Electronic                mail       RTR      RARE Technical Report (series of RARE publications)       RTS      Reliable Transfer Service       WG-MSG   RARE Working Group on Mail and Messaging



 RARE WG-MSG Task Force 88                                      [Page 37]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 Appendix A - Elaboration on the main recommendations

   The main recommendations of the report are elaborated upon in more    detail within this appendix.

    - In order to provide a globally pervasive messaging service,       it is recommended to establish a well operated Pan-European       X.400(1988) pilot backbone comprising MTAs and MSs,       connecting partners within Industry, Commercial Service       Providers, Academia and Public Bodies (CEC, National       Governments, etc.). The pilot should be open to global       participation.

    - In order to maintain the widest connectivity with the       highest possible functionality, gateways should be installed       that gateway between X.400(1988) and RFC 822/MIME. These       gateways should follow the specifications of RFC 1327 [1] and       RFC 1494 et al. [4]. Experience with these gateways should be       fed back into the appropriate RARE and IETF Working Groups to       improve the standards.

    - In order that the 'business needs' of non-R&D organisations       can be inserted at an early stage into the goals of the pilot       and ensuring that the success of the pilot in meeting these       goals can be measured and disseminated i.e., to encourage the       active participation of non-R&D organisations within the       pilot, it is recommended that an open forum comprising       industry, service providers, public bodies and academia       should be used. Preferably an existing forum where end users       are heavily involved is desirable.

    - In order for meaningful co-operation between bodies affected       by the pilot to occur and thus hopefully reducing unnecessary       duplications, it is recommended that there are close liaisons       and contacts between at least the IETF, RARE, EARN, EUnet,       RIPE, Y-NET, EEMA, EMA, EWOS, OIW, CEN/CENELEC, ISO, CCITT,       CEC and European governmental bodies and those involved       within the pilot. The suggested mechanism for a meaningful       liaison is that enough participants of the above       organisations attend the common forum mentioned above. It is       also suggested that as much as possible e-mail distribution       lists be used to communicate between forum participants.

    - In order that the pilot have measurable results, it is       recommended that the pilot shall be implemented in phases. It       is considered that at least two phases are needed:





RARE WG-MSG Task Force 88                                      [Page 38]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

          - phase 1 - initial short start up phase with a small            number of participants. The result of this phase is            that any needed procedures, co-ordination mechanisms,            etc. are put into place for the large scale piloting of            phase 2.

         - phase 2 - phase with a wide Pan-European participation.            The result of this phase should be a proof of scaling            of the pilot X.400(1988) service i.e., the goals of the            pilot as defined in Chapter 1 are met. It is expected            that upon successful completion of this phase a natural            evolution to a global deployment of a X.400(1988)            service will have started.

    - In order to rapidly complete phase 1 of the pilot and that       the pilot is at least Pan-European in scope, it is       recommended that; a number of R&D service providers, one each       from several European countries; at least 2 North American       R&D service providers; at least 1 Japanese R&D service       provider and a small number of commercial service providers       and commercial organisations are actively involved in phase       1.

    - In order to stimulate the creation of an economically viable       market place for X.400(1988) products (i.e., MTAs, UAs, etc.)       (i.e., users are willing to purchase such products), it is       recommended that a suitable minimum number of new software       implementations and or modifications to existing software       implementations be funded. The resulting software to be       inserted into the Public Domain free of any financial       restrictions on further commercial exploitation. By using       this mechanism, Small and Medium Size Enterprises (SMEs) will       be encouraged to commercially exploit such products.

    - Due to the strong influence of the R&D community within the       pilot plus the desire to produce standardised products       quickly and pragmatically, it is recommended that any       standards proposed within the scope of an X.400(1988) pilot       (for example standards re: character sets and body parts       gatewayed to and from X.400(1988) and RFC 822 / MIME) are       conformant to and candidates for Internet standardisation. As       a concrete example of the standardisation process, this means       that at least two independent software implementations, for       each product category, (of which one product preferably in       the Public Domain) must be proven as interworking to a       proposed standard before the proposed standard can be       elevated to draft standard [20].



 RARE WG-MSG Task Force 88                                      [Page 39]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

     - To ensure that there is a market driven demand for       X.400(1988) products within the commercial market place, it       is recommended that the maximum number of Public Domain       implementations that are funded, by any one public funding       organisation, is two. It is desirable that at least one other       product, preferably commercially based and not within the       Public Domain, is produced.

    - In order that any necessary information required for the       effective operation of the X.400(1988) pilot, including not       least OID assignments, mapping rules, information about       interconnection partners, naming authority information be       made widely available, it is recommended that an       electronically accessible information base be established.

    - In order that any necessary organisational issues needed for       a deployment of an X.400(1988) service have a body in place       to deal with this issue, it is recommended that the pilot       either identify and list which bodies are responsible for       which issues or else actively ensure that a suitable body is       being put in place.

Appendix B - A number of detailed guidelines.

   The Task Force has the following detailed guidelines:

*Product and operational service guidelines*

    - To ensure that there is no degradation of X.400(1988)       service between X.400(1988) originators and destinations, the       topology of the MTS must be such that no X.400(1984) MTA acts       as a relay between any two X.400(1988) users.

    - As the existing R&D X.400(1984) service (formerly COSINE       MHS) now comprises a large number of X.400(1988) capable       RELAYs, it would be relatively straight forward that the       existing COSINE MHS RELAYs be one of the first communities       that are migrated to X.400(1988) capabilities. This would       ensure that X.400(1988) MTAs using the RELAY backbone       experience no loss of service.

    - To be able to operate an X.400(1988) service a properly       operated X.400(1988) infrastructure should be established,       consisting of X.400(1988) MTAs, X.400(1988) MTAs with       downgrading capabilities according to RTR 3, Message Store       services and gateways to RFC 822 based upon RTR 2 and       extended gatewaying functionality for multimedia mail.



 RARE WG-MSG Task Force 88                                      [Page 40]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

     - To ensure maximum use of the OSI supporting layers plus       support of normal mode RTS, it is recommended that a       migration to ISO 10021 is effected i.e., straight to use of       the full OSI stack with normal mode RTS.

    - To ensure maximum quality of service as impacted by       implementation decisions related to the 'General Extension       Mechanism', it is recommended that no minimal X.400(1988)       MTAs, which relay the syntax but understand none of the       semantics of extensions, should be used.

    - It is recommended that all X.400(1988) MTAs should generate       reports containing extensions copied from the subject message       and route reports through the DL expansion hierarchy where       appropriate.

    - It is recommended that all X.400(1984) UAs are able to       generate and display DDAs. This will allow such systems to       address X.400(1988) Common Name Attribute users.

    - To enhance connectivity to both X.400(1984 and 1988)       management domains without degradation of X.400(1988)       service, management domain entry points that support both       X.400(1984 and 1988) are recommended.

    - To ensure total connectivity between RFC 822 domains       migrating to X.400(1988), it is recommended that a local       X.400-to-RFC-822 gateway is made operational or a reliable       service agreement for the external provision of such a       gateway is effected before any migration begins.

*Migration utilities needed*

    - It is considered very helpful if conversion utilities that       allow a flawless conversion of an RFC 822 user's existing       mail folders to a X.400(1988) product's folder system be       implemented. However further investigation is needed before       recommending that such tools be made a mandatory part of any       funded software development.

    - It is recommended that the ease of configuration of       X.400(1988) products is made as automatic as possible.       Consideration should be given to a) modern user interfaces b)       automatic processing of 'old RFC 822' configuration files       into the 'new X.400(1988)' configuration files i.e., a reuse       of the user's previous options and configurations should be       the result. If a 'simple' configuration interface is needed       it should be as compatible as possible with the present RFC



RARE WG-MSG Task Force 88                                      [Page 41]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

       822 mailer's i.e., this concretely means editing of ASCII       files.

*Issues for further study*

   The pilot X.400(1988) messaging service must ensure that the issues    listed below are either being investigated by an appropriate body or    if not initiate actions to properly address them. The issues have    been grouped under Products, Organisational and Deployment.

    - Products

         - Any X.500 DSAs, DUAs, APIs e.g., LDAP, etc. changes            needed to support X.400(1988) messaging.

         - X.400(1988) MTAs, UAs, MSs, gateways to RFC 822/MIME            and X.400(1984) plus gateways to other messaging            systems e.g., Microsoft Mail, Lotus cc:Mail, etc.

         - User Interfaces that integrate X.400(1988) UAs and            X.500 DUAs with user applications such as Word            Processors, etc.

         - E-mail network management software both for users and            administrators

    - Organisational

         - trusted network for security (i.e., the distribution of            security keys) and whether this trusted network should            or can be the same as the PEM trusted network presently            under deployment.

         - usage of PEM within X.400(1988).

         - PEM to and from X.400(1988) gatewaying.

         - how to register and publicise object IDs for            X.400(1988).

         - addresses are well publicised of PRMD and ADMD            registration authorities.

         - creation and modification authority for X.400-to-RFC-            822 mapping rules is defined.

         - creation and modification authority for MTA routing            rules is defined.



RARE WG-MSG Task Force 88                                      [Page 42]
 RFC 1616     X.400(88) for European Academics and Research      May 1994



         - what methods should be used to liaison to other bodies            like IETF, ISO, EEMA, EMA, etc.

         - ensuring that any Public Domain software needed for the            X.400(1988) service is distributed widely, quickly and            efficiently.

    - Deployment

         - which services should start such a migration (i.e.,            COSINE MHS RELAYs, Universities, other).

         - the topology of the X.400(1988) MTS.

         - addressing of users between X.400(1984 and 1988) and            RFC 822 e.g., how will X.400(1988) T.61 address            components be processed by X.400(1984) and RFC 822            systems.

         - which X.400(1988) body parts MUST be supported by the            research community.

         - if any new APIs - or modified APIs - are needed for            X.400(1988) and messaging in general.

         - the specifications and development of any needed Public            Domain software.

         - what existing Public Domain software should be modified            to accommodate X.400(1988) systems.

         - how rapidly to deploy the X.400(1988) service.

         - ensuring that there is 'little or no loss of service'            in any migration from X.400(1984), or RFC 822, to            X.400(1988).

         - considering what Value Added Services, based upon            X.400(1988), could be started to encourage uptake of            X.400(1988).









 RARE WG-MSG Task Force 88                                      [Page 43]
 RFC 1616     X.400(88) for European Academics and Research      May 1994

 Authors' Addresses

   Only the two editors' complete addresses are listed here:

   Erik Huizer (Task Force chair)    SURFnet bv    P.O. Box 19035    NL-3501 DA  Utrecht    Europe

   Phone: [phone]    RFC 822: [e-mail]    X.400:   S=huizer;O=SURFnet;PRMD=surf;ADMD=400net;C=nl;

    James A. (Jim) Romaguera    NetConsult AG    Berner Technopark    Morgenstrasse 129    CH-3018 Bern    Europe

   Phone: [phone]    RFC 822: [e-mail]    X.400: S=romaguera;O=netconsult;PRMD=SWITCH;ADMD=ARCOM;C=CH;

   The Task Force as a whole can be reached per e-mail at the    address:

   RFC 822: [e-mail]    X.400:   S=tf-88;O=SURFnet;PRMD=surf;ADMD=400net;C=nl;



















 RARE WG-MSG Task Force 88                                      [Page 44]