RFC 1069 (rfc1069) - Page 2 of 10

Guidelines for the use of Internet-IP addresses in the ISO Connectionless-Mode Network Protocol

RFC 1069                   IP ISO Addressing               February 1989


   regard to the ISO addressing within the CLNP.  In particular, the ISO
   network layer addressing standard allows a great deal of flexibility
   in the assignment of addresses, and a particular address format must
   be chosen.  A further problem is the need for implementation and
   integration of routing facilities for the ISO-compatible subset of
   the Internet environment.

   This paper proposed to use addresses which are considerably more
   flexible than the addresses used in the current IP Internet
   environment.  This flexibility is necessary in order to allow some
   routing domains to base their internal routing protocol on addresses
   derived from the current IP addresses, to allow other routing domains
   to base routing on addresses in accordance to the intra-domain
   routing protocol being developed by ANSI and ISO [6], and to allow
   generality for a future inter-domain routing protocol.

   The addressing scheme proposed here makes use of the concept of
   "routing domains" as used in ANSI and ISO.  This concept is similar
   to, but not identical with, the concept of "Autonomous System" used
   in the Internet.  Routing domains include a combination of gateways,
   networks, and end systems (not just gateways), and routing domain
   boundaries may be used to define associated access control and policy
   routing constraints.  Like autonomous systems, routing domains may be
   assumed to be topologically contiguous.  There is no a priori reason
   why routing domains assigned for use with the ISO IP need to have any
   particular relation with existing autonomous systems which have been
   assigned for use with the IP.  The assignment of specific routing
   domain identifiers is an "assigned numbers" function which is
   necessary for use of the ISO IP in the Internet, but is beyond the
   scope of this document.

   It is expected that this addressing scheme will be appropriate for
   long term use with the ISO IP in the Internet.  However, it is also
   expected that in the long term, the Internet will be interconnected
   with other routing domains making use of other schemes, such as
   addresses assigned to commercial internets through ANSI, and
   addresses assigned by national standards organizations in other
   countries.  This implies that, in the long term, gateways in the
   Internet will need to be able to route datagrams to destinations in
   other routing domains not conforming to the addressing format
   proposed here.  This is discussed in greater detail in section 6.

2.  Introduction

   The CLNP is documented in [1], but for matters of completeness the
   following illustration of the CLNP header is included here as Figure
   1.




Callon & Braun