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RFC 1167                          NREN                         July 1990


      direct subsidies should diminish over time and that the
      intermediate networks should become self-sustaining.  To
      accomplish this objective, the intermediate-level networks have
      been turning to an increasingly diverse user constituency (see
      section above).

      The basic model of government backbones, consortium intermediate
      level nets and private local area networks has served reasonably
      well during the 1980's but it would appear that newer
      telecommunications technologies may suggest another potential
      paradigm.  As the NSFNET moves towards higher speed backbone
      operation in the 45 Mb/s range, the importance of carrier
      participation in the enterprise has increased.  The provision of
      backbone capacity at attractive rates by the inter-exchange
      carrier (in this case, MCI Communications Corporation) has been
      crucial to the feasibility of deploying such a high speed system.

      As the third phase of the NREN effort gets underway, it is
      becoming increasingly apparent that the "federally-funded
      backbone" model may and perhaps even should or must give way to a
      vision of commercially operated, gigabit speed systems to which
      the users of the NREN have access.  If there is federal subsidy in
      the new paradigm, it might come through direct provision of
      support for networking at the level of individual research grant
      or possibly through a system of institutional vouchers permitting
      and perhaps even mandating institution-wide network planning and
      provision.  This differs from the present model in which the
      backbone networks are essentially federally owned and operated or
      enjoy significant, direct federal support to the provider of the
      service.

      The importance of such a shift in service provision philosophy
      cannot be over-emphasized.  In the long run, it eliminates
      unnecessary restrictions on the use and application of the
      backbone facilities, opening up possibilities for true ubiquity of
      access and use without the need for federal control, except to the
      extent that any such services are considered in need of
      regulation, perhaps.  The same arguments might be made for the
      intermediate level systems (metropolitan and regional area access
      networks).  This does NOT mean that private networks ranging from
      local consortia to inter-continental systems will be ruled out.
      The economics of private networking may still be favorable for
      sufficiently heavy usage.  It does suggest, however, that
      achieving scale and ubiquity may largely rely on publicly
      accessible facilities.






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RFC 1167                          NREN                         July 1990


   The Vendors

      Apart from service provision, the technology available to the
      users and the service providers will come largely from commercial
      sources.  A possible exception to this may be the switches used in
      the gigabit testbed effort, but ultimately, even this technology
      will have to be provided commercially if the system is to achieve
      the scale necessary to serve as the backbone of the NREN.

      An important consequence of this observation is that the NREN
      architecture should be fashioned in such a way that it can be
      constructed from technology compatible with carrier plans and
      available from commercial telecommunications equipment suppliers.
      Examples include the use of SONET (Synchronous Optical Network)
      optical transmission technology, Switched Multimegabit Data
      Services offerings (metropolitan area networks), Asynchronous
      Transmission Mode (ATM) switches, frame relays, high speed,
      multi-protocol routers, and so on.  It is somewhat unclear what
      role the public X.25 networks will play, especially where narrow
      and broadband ISDN services are available, but it is also not
      obvious that they ought to be written off at this point.  Where
      there is still research and development activity (such as in
      network management), the network R&D community can contribute
      through experimental efforts and through participation in
      standards-making activities (e.g., ANSI, NIST, IAB/IETF, Open
      NMF).

OPERATIONS

   It seems clear that the current Internet and the anticipated NREN
   will have to function in a highly distributed fashion.  Given the
   diversity of service providers and the richness of the constituent
   networks (as to technology and ownership), there will have to be a
   good deal of collaboration and cooperation to make the system work.
   One can see the necessity for this, based on the existing voice
   network in the U.S.  with its local and inter-exchange carrier (IEC)
   structure.  It should be noted that in the presence of the local and
   IEC structure, it has proven possible to support private and virtual
   private networking as well.  The same needs to be true of the NREN.

   A critical element of any commercial service is accounting and
   billing.  It must be possible to identify users (billable parties,
   anyway) and to compute usage charges.  This is not to say that the
   NREN component networks must necessarily bill on the basis of usage.
   It may prove preferable to have fixed access charges which might be
   modulated by access data rate, as some of the intermediate-level
   networks have found.  It would not be surprising to find a mixture of
   charging policies in which usage charges are preferable for small



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RFC 1167                          NREN                         July 1990


   amounts of use and flat rate charges are preferred for high volume
   use.

   It will be critical to establish a forum in which operational matters
   can be debated and methods established to allow cooperative operation
   of the entire system.  A number of possibilities present themselves:
   use of the Internet Engineering Task Force as a basis, use of
   existing telecommunication carrier organizations, or possibly a
   consortium of all service providers (and private network operators?).
   Even if such an activity is initiated through federal action, it may
   be helpful, in the long run, if it eventually embraces a much wider
   community.

   Agreements are needed on the technical foundations for network
   monitoring and management, for internetwork accounting and exchange
   payments, for problem identification, tracking, escalation and
   resolution.  A framework is needed for the support of users of the
   aggregate NREN.  This suggests cooperative agreements among network
   information centers, user service and support organizations to begin
   with.  Eventually, the cost of such operations will have to be
   incorporated into the general cost of service provision.  The federal
   role, even if it acts as catalyst in the initial stages, may
   ultimately focus on the direct support of the users of the system
   which it finds it appropriate to support and subsidize (e.g., the
   research and educational users of the NREN).

   A voucher system has been proposed, in the case of the NREN, which
   would permit users to choose which NREN service provider(s) to
   engage.  The vouchers might be redeemed by the service providers in
   the same sort of way that food stamps are redeemed by supermarkets.
   Over time, the cost of the vouchers could change so that an initial
   high subsidy from the federal government would diminish until the
   utility of the vouchers vanished and decisions would be made to
   purchase telecommunications services on a pure cost/benefit basis.

IMPORTANCE OF COMMERCIAL INTERESTS

   The initial technical architecture should incorporate commercial
   service provision where possible so as to avoid the creation of a
   system which is solely reliant on the federal government for its
   support and operation.  It is anticipated that a hybrid system will
   develop but, for example, it is possible that the gigabit backbone
   components of the system might be strictly commercial from the start,
   even if the lower speed components of the NREN vary from private, to
   public to federally subsidized or owned and operated.






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RFC 1167                          NREN                         July 1990


CONCLUSIONS

   The idea of creating a National Research and Education Network has
   captured the attention and enthusiasm of an extraordinarily broad
   collection of interested parties.  I believe this is in part a
   consequence of the remarkable range of new services and facilities
   which could be provided once the network infrastructure is in place.
   If the technology of the NREN is commercially viable, one can readily
   imagine that an economic engine of considerable proportions might
   result from the widespread accessibility of NREN-like facilities to
   business sector.

Security Considerations

   Security issues are not discussed in this memo.

Author's Address

   Vinton G. Cerf
   Corporation for National Research Initiatives
   1895 Preston White Drive, Suite 100
   Reston, VA 22091

   EMail: [e-mail]

   Phone: [phone]

























Cerf                                                            [Page 8]