rfc1210.txt

著名的RFC文档,其中有一些文档是已经翻译成中文的的.

   instructions given in the opening plenary sessions, were to identify
   the following:

   (i)   user requirements which must be satisfied to support
         cooperative US/European research;

   (ii)  technical and other infrastructure requirements which must be
         satisfied to support cooperative US/European research;

   (iii) opportunities and potential means for satisfying these
         requirements;

   (iv)  potential obstacles to achieving the desired support;

   (v)   mutual benefits which would accrue to the participants in
         recommended cooperative projects;

   (vi)  promising collaborative development activities needed for
         a better infrastructure.

3.  MOTIVATION FOR COLLABORATION ON NETWORKING AND INFRASTRUCTURE

   Computer networking, by its very nature, requires cooperation and
   collaboration among the participants developing, implementing,
   deploying and operating the hardware and software comprising the
   system.  The long-term vision is the creation of an infrastructure
   which provides the user (rather than the network) with a distributed
   multi-vendor heterogeneous computing environment - with transatlantic
   facilities approaching those available locally.

   A major element of successful networking is the agreement on
   standards which are to be met by all systems included in the network.
   Beyond technical agreements, there must also be concurrence on
   operational procedures, performance objectives, support for the users
   of the network and ability to plan for enhancement and growth of



Cerf, Kirstein, & Randell                                       [Page 6]

RFC 1210      Network and Infrastructure User Requirements    March 1991


   network services.

   A consequence of these observations is that virtually any effort to
   provide network service support to ESPRIT-DARPA/NSF collaboration
   should be carried out cooperatively between the US and European
   network research, design, development, engineering and operations
   communities.

4.  CURRENT STATE OF NETWORKING IN THE US AND EUROPE

   In the DARPA/NSF communities, there is heavy use of electronic mail
   and computer networking to support a wide range of scientific
   research.  There is heavy use of the TCP/IP and DECNET protocols as
   well as special electronic mail protocols in the BITNET and Unix
   users networks (e.g., UUNET).  Email use varies in intensity among
   different research disciplines.

   There is an emerging interest in and use of OSI-based protocols,
   particularly for email (X.400) and directory services (X.500).  Most
   of the backbone networks making up the Internet use 1.5 Mb/s
   telecommunications facilities although the NSFNET will be installing
   a high speed, 45 Mb/s subnetwork during 1990.  There are many Local
   Area Networks (LANs).  Plans are in place to support both IP (as in
   TCP/IP) and CLNP (as in OSI) datagram protocols in backbone and
   regional networks.  Most of these protocols are already supported on
   LANs.  On a selective research basis, a set of 1000 Mb/s research
   testbeds are being installed during 1990-1993.

   In Europe, especially amongst the ESPRIT collaborators, there is more
   limited use of computer networking, with the primary emphasis on the
   use of electronic mail and bulletin boards.  There is a strong focus
   on OSI protocols in European wide-area networks, but there is a
   considerably amount of TCP/IP use on LANs, and growing use of TCP/IP
   in Wide Area Networks (WANs) in some countries.  Most of the national
   wide-area networks are based on the CCITT X.25 protocols with access
   speeds up to 64 Kb/s, though higher access speeds in the 2 Mb/s range
   are planned for many countries, and just becoming available in some.
   An X.25 international backbone (IXI) has just become operational,
   which connects in the National Research Networks and/or the Public
   Packet Data Networks in each Western Europe country at 64 Kb/s.  The
   funding of this network has only been agreed for a further short
   period, and plans to upgrade it to higher speed access are not
   agreed.  There are many LANs in place.  The OSI connection-oriented
   network service (CONS) is layered above X.25, but there is growing
   interest in supporting the connectionless service (CLNS) concurrently
   with the Internet IP in national and international backbone networks.
   Application testbeds at higher speeds are planned under the CEC RACE
   programme.  Many of its higher level user services have not been



Cerf, Kirstein, & Randell                                       [Page 7]

RFC 1210      Network and Infrastructure User Requirements    March 1991


   specified collaboratively - as would be required for wide deployment.
   These points are explained further in Section 6.

   Thus although provisions or plans regarding National networks in some
   CEC member states are not so far behind the American facilities, one
   must note that in effect, because of continental backbone
   limitations, Pan-European facilities are at least a generation
   behind.  Specifically, both with respect to existing and planned
   backbone provisions, there is a factor of 25 difference between
   Europe and the USA.  In addition, this approximate comparison
   flatters the European scene, since it compares facilities that are
   just coming into existence, and plans that are not yet agreed or
   funded, on the European side with facilities that have been available
   for some time, and plans that will be realised before the end of this
   year, in the USA.

5.  POLLS OF THE OTHER WORKING GROUPS

   The NIWG polled the other seven working groups meeting in Brussels
   and Washington to find out what networking and infrastructure support
   their collaborations might require.  In general, a strong emphasis
   was placed on the provision of reliable and timely email, easier
   accessibility of email service, user support and information on
   existence and use of available services.  There was serious concern
   about privacy, and great interest in transparency (i.e., hiding the
   details of intercontinental networking).

   Some users mentioned that FAX was easier to use and apparently more
   ubiquitous than email for their communities (there are over 12 M
   facsimile machines installed world-wide).  Interest in integrating
   FAX and email was noticeable.  Most users recognised the many
   advantages of email for multiple addressees, subsequent reprocessing,
   relaying and cost.

   The requirement for large file transfer was patchy.  Many did not
   require such facilities, but several groups required transfer of 100
   MB files and some even 1 GB.  Many groups desired remote log-in, but
   found present performance - even on the Internet - inadequate.
   Several wanted global file services and file sharing.

   Many groups wished to use video conferencing - but only if they did
   not have to travel more than two hours to a suitable facility.  Some
   groups were interested in computer supported group collaboration -
   but most did not understand this term.

   One group (Vision) desired real time transfer at 300 Mb/s, but most
   had much more modest user-user needs.  The needs for less visible
   features like network management, client-user technology, remote



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RFC 1210      Network and Infrastructure User Requirements    March 1991


   visualization standards and data representation and exchange formats
   were not voiced explicitly.  However they could be deduced from the
   services which the users did request.

6. USER SERVICES NEEDED IN THE SHORT AND MEDIUM TERM

   To support collaboration between the research workers, we need a
   number of services between the end users.  These require provisions
   which impinge on many management domains: inside individual campuses;
   campus-wide area gateways; national distribution; regional-
   intercontinental gateways; intercontinental distribution.  However,
   from the users' viewpoint, this set of services should constitute a
   system whose internal details are not, or at least should not, be of
   concern.  It is the overall performance and reliability exhibited,
   and the facilities made available to the user (and their cost), which
   matter.  Inadequacies of bandwidth, protocols, or administrative
   support anywhere in the chain between the end users are, to them,
   inadequacies in the system as a whole.

   To some extent more funding from DARPA/NSF and the CEC can alleviate
   the current difficulties.  However it is likely that such funding
   will impact only the international and intercontinental components.
   It is essential that the end-user distribution be strengthened also.
   In the US this requires both Regional and Campus Networks.  In
   Europe, it requires activity by the National network authorities
   (usually represented in RARE and/or COSINE), and by the Campus
   network providers.  Moreover, not only must the transmission
   facilities be strengthened, but also the appropriate protocol suites
   must be supported; this may require policy decisions as well as
   technical measures.

   We indicate below the services which are required immediately, and
   are visible to the end-users.  They often have implications to the
   service providers which have far-reaching consequences.  Some of the
   services are urgent user services; some are underpinning requirements
   needed to assure the user services; some are longer term needs.
   There is clearly a strong interaction between the user services and
   the underpinning ones; there is also some between the user services
   themselves.  Partly as a result of our own deliberations, and partly
   as a result of our polls of the other working groups, we have
   identified needs in the areas below.

USER SERVICES

   In most cases these are services which are available in local or
   homogeneous environments.  For the proposed collaborations they must
   be available on an intercontinental basis between heterogeneous
   systems.



Cerf, Kirstein, & Randell                                       [Page 9]

RFC 1210      Network and Infrastructure User Requirements    March 1991


6.1  Electronic Mail

   The current email services between the US and Europe suffer from gaps
   in connectivity, lack of reliability and poor responsiveness.  These
   problems stem, in part, from the multiplicity of protocols used (and
   requiring translation) and in part from an inadequate operations and
   maintenance infrastructure.  There are few user and directory support
   services available; access to, and use of, email service varies
   dramatically.  However, some initial cooperative work has started
   already between RARE Working Group 1 and participants in the Internet
   Engineering Task Force in the area of email.

6.1.1  One Year Targets

   (i)  Provide management structure to support user assistance and
        reliable operation of email relays;

   (ii) Achieve routine expectation of proper and timely (less than
        1 hour campus-campus) delivery.

6.1.2  Three Year Targets

   (i)   Provide global, email directory services;

   (ii)  Develop and deploy a return/receipt facility;

   (iii) Provide support for privacy and authenticity.

6.1.3  Recommended Actions

   (i)   Initiate an intercontinental email operations forum involving
         email service providers in the US and Europe to define and
         implement operational procedures leading to high reliability;

   (ii)  Task the email operations forum to develop functional and
         performance specifications for email gateways (relays);

   (iii) Organize an international email user support group;

   (iv)  Organize a collaborative working group to analyse email
         interoperability problems (X.400, UUCP, SMTP, EARN, EUROKOM,
         BITNET) and make recommendations for specific developments to
         improve interoperability.

   Included in the terms of reference should be requirements for
   cryptographic support for privacy, authenticity and integrity of
   email.  This work could include specific collaboration on X.400 and
   SMTP privacy enhancement methods.  (Note there are serious



Cerf, Kirstein, & Randell                                      [Page 10]

RFC 1210      Network and Infrastructure User Requirements    March 1991


   international obstacles to achieving progress in areas involving
   cryptographic technology.)

   See Directory Services section for further possible actions.

6.2  Compound Document Electronic Mail

   While proprietary solutions for compound documents (text, font
   support, geometric graphics, bit-map graphic, spread-sheets, voice
   annotation, etc.) exist, these are limited to products of single
   manufacturers.  While international standards for compound documents
   exist, these are still evolving, and few real commercial products
   based on the standards exist.  Nevertheless, both proprietary and
   open systems compound document mail services could be made available
   reasonably quickly.

6.2.1  One Year Targets

   (i)  Support proprietary compound document email for groups
        interested in using specific conforming products;

   (ii) Provide experimental services to groups with open systems
        offerings using several products.  Support interoperation
        for multi-font text, bit-mapped and geometric graphics.  The
        software could be provided from that arising from the
        combination of a previous NSF and an ESPRIT proposal.

6.2.2  Three Year Targets

   Provide support for open system compound document email and document
   exchange including the following facilities: spreadsheets; integrity,
   authentication and non-repudiation of origin of document parts;