RFC 1126 (rfc1126) - Page 2 of 25

Goals and functional requirements for inter-autonomous system routing

RFC 1126            Inter-Autonomous System Routing         October 1989


   tradeoff considerations and the like have been purposefully omitted
   in support of this.  An appendix has been included which addresses
   this omission to a limited extent and the reader is directed there
   for a more detailed discussion of the issues involved.

   The goals and functional requirements contained in this document are
   the result of work done by the members of the Open Routing Working
   Group.  It is our intention that these goals and requirements reflect
   not only those foreseen in the Internet community but are also
   similar to those encountered in environments proposed by ANSI, ECMA
   and ISO.  It is expected that there will be some interaction and
   relationship between this work and the product of these groups.

2.  Overall Goals

   In order to derive a set functional requirements there must be one or
   more principals or overall goals for the routing environment to
   satisfy.  These high level goals provide the basis for each of the
   functional requirements we have derived and will guide the design
   philosophy for achieving an inter-autonomous system routing solution.
   The overall goals we are utilizing are described in the following
   sections.

2.1  Route to Destination

   The routing architecture will provide for the routing of datagrams
   from a single source to one or more destinations in a timely manner.
   The larger goal is to provide datagram delivery to an identifiable
   destination, one which is not necessarily immediately reachable by
   the source.  In particular, routing is to address the needs of a
   single source requiring datagram delivery to one or more
   destinations.  The concepts of multi-homed hosts and multicasting
   routing services are encompassed by this goal.  Datagram delivery is
   to be provided to all interconnected systems when not otherwise
   constrained by autonomous considerations.

2.2  Routing is Assured

   Routing services are to be provided with assurance, where the
   inability to provide a service is communicated under best effort to
   the requester within an acceptable level of error.  This assurance is
   not to be misconstrued to mean guaranteed datagram delivery nor does
   it imply error notification for every lost datagram.  Instead,
   attempts to utilize network routing services when such service cannot
   be provided will result in requester notification within a reasonable
   period given persistent attempts.





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