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Network Working Group                                          R. Colella
Request for Comments: 1629                                           NIST
Obsoletes: 1237                                                 R. Callon
Category: Standards Track                                       Wellfleet
                                                               E. Gardner
                                                                    Mitre
                                                               Y. Rekhter
                                   T.J. Watson Research Center, IBM Corp.
                                                                 May 1994


           Guidelines for OSI NSAP Allocation in the Internet

Status of this Memo

   This document specifies an Internet standards track protocol for the
   Internet community, and requests discussion and suggestions for
   improvements.  Please refer to the current edition of the "Internet
   Official Protocol Standards" (STD 1) for the standardization state
   and status of this protocol.  Distribution of this memo is unlimited.

Abstract

   CLNP is currently being deployed in the Internet.  This is useful to
   support OSI and DECnet(tm) traffic.  In addition, CLNP has been
   proposed as a possible IPng candidate, to provide a long-term
   solution to IP address exhaustion.  Required as part of the CLNP
   infrastructure are guidelines for network service access point (NSAP)
   address assignment.  This paper provides guidelines for allocating
   NSAP addresses in the Internet.

   The guidelines provided in this paper have been the basis for initial
   deployment of CLNP in the Internet, and have proven very valuable
   both as an aid to scaling of CLNP routing, and for address
   administration.
















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RFC 1629                    NSAP Guidelines                     May 1994


Table of Contents

   Section 1. Introduction ...............................    4
   Section 2. Scope ......................................    5
   Section 3. Background .................................    7
   Section 3.1 OSI Routing Standards .....................    7
   Section 3.2 Overview of IS-IS (ISO/IEC 10589) .........    8
   Section 3.3 Overview of IDRP (ISO/IEC 10747) ..........   12
   Section 3.3.1 Scaling Mechanisms in IDRP ..............   14
   Section 3.4 Requirements of IS-IS and IDRP on NSAPs ...   15
   Section 4. NSAPs and Routing ..........................   16
   Section 4.1 Routing Data Abstraction ..................   16
   Section 4.2 NSAP Administration and Efficiency ........   19
   Section 5. NSAP Administration and Routing in the In-
        ternet ...........................................   21
   Section 5.1 Administration at the Area ................   23
   Section 5.2 Administration at the Subscriber Routing
        Domain ...........................................   24
   Section 5.3 Administration at the  Provider  Routing
        Domain ...........................................   24
   Section 5.3.1 Direct Service Providers ................   25
   Section 5.3.2 Indirect Providers ......................   26
   Section 5.4 Multi-homed Routing Domains ...............   26
   Section 5.5 Private Links .............................   31
   Section 5.6 Zero-Homed Routing Domains ................   33
   Section 5.7 Address Transition Issues .................   33
   Section 6. Recommendations ............................   36
   Section 6.1 Recommendations Specific to U.S. Parts of
        the Internet .....................................   37
   Section 6.2  Recommendations Specific to European Parts
        of the Internet ..................................   39
   Section 6.2.1 General NSAP Structure ..................   40
   Section 6.2.2 Structure of the Country Domain Part ....   40
   Section  6.2.3  Structure of the Country Domain
        Specific Part ....................................   41
   Section 6.3 Recommendations Specific to Other Parts of
        the Internet .....................................   41
   Section 6.4 Recommendations for Multi-Homed Routing
        Domains ..........................................   41
   Section 6.5 Recommendations for RDI and RDCI assign-
        ment .............................................   42
   Section 7. Security Considerations ....................   42
   Section 8. Authors' Addresses .........................   43
   Section 9. Acknowledgments ............................   43
   Section 10. References ................................   44
   Section A. Administration of NSAPs ....................   46
   Section A.1  GOSIP Version 2 NSAPs ....................   47
   Section A.1.1  Application for Administrative Authority



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RFC 1629                    NSAP Guidelines                     May 1994


        Identifiers ......................................   48
   Section A.1.2  Guidelines for NSAP Assignment .........   50
   Section A.2  Data Country Code NSAPs ..................   50
   Section A.2.1  Application for Numeric Organization
        Name .............................................   51
   Section A.3  Summary of Administrative  Requirements ..   52













































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RFC 1629                    NSAP Guidelines                     May 1994


1.  Introduction

   The Internet is moving towards a multi-protocol environment that
   includes CLNP.  To support CLNP in the Internet, an OSI lower layers
   infrastructure is required.  This infrastructure comprises the
   connectionless network protocol (CLNP) [9] and supporting routing
   protocols.  Also required as part of this infrastructure are
   guidelines for network service access point (NSAP) address
   assignment.  This paper provides guidelines for allocating NSAP
   addresses in the Internet (the terms NSAP and NSAP address are used
   interchangeably throughout this paper in referring to NSAP
   addresses).

   The guidelines presented in this document are quite similar to the
   guidelines that are proposed in the Internet for IP address
   allocation with CIDR (RFC 1519 [19]).  The major difference between
   the two is the size of the addresses (4 octets for CIDR vs 20 octets
   for CLNP).  The larger NSAP addresses allows considerably greater
   flexibility and scalability.

   The remainder of this paper is organized into five major sections and
   an appendix.  Section 2 defines the boundaries of the problem
   addressed in this paper and Section 3 provides background information
   on OSI routing and the implications for NSAP addresses.

   Section 4 addresses the specific relationship between NSAP addresses
   and routing, especially with regard to hierarchical routing and data
   abstraction.  This is followed in Section 5 with an application of
   these concepts to the Internet environment.  Section 6 provides
   recommended guidelines for NSAP address allocation in the Internet.
   This includes recommendations for the U.S. and European parts of the
   Internet, as well as more general recommendations for any part of the
   Internet.

   The Appendix contains a compendium of useful information concerning
   NSAP structure and allocation authorities.  The GOSIP Version 2 NSAP
   structure is discussed in detail and the structure for U.S.-based DCC
   (Data Country Code) NSAPs is described.  Contact information for the
   registration authorities for GOSIP and DCC-based NSAPs in the U.S.,
   the General Services Administration (GSA) and the American National
   Standards Institute (ANSI), respectively, is provided.

   This document obsoletes RFC 1237.  The changes from RFC 1237 are
   minor, and primarily editorial in nature.  The descriptions of OSI
   routing standards contained in Section 3 have been updated to reflect
   the current status of the relevant standards, and a description of
   the OSI Interdomain Routing Protocol (IDRP) has been added.
   Recommendations specific to the European part of the Internet have



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RFC 1629                    NSAP Guidelines                     May 1994


   been added in Section 6, along with recommendations for Routing
   Domain Identifiers and Routing Domain Confederation Identifiers
   needed for operation of IDRP.

2.  Scope

   Control over the collection of hosts and the transmission and
   switching facilities that compose the networking resources of the
   global Internet is not homogeneous, but is distributed among multiple
   administrative authorities.  For the purposes of this paper, the term
   network service provider (or just provider) is defined to be an
   organization that is in the business of providing datagram switching
   services to customers.  Organizations that are *only* customers
   (i.e., that do not provide datagram services to other organizations)
   are called network service subscribers (or simply subscribers).

   In the current Internet, subscribers (e.g., campus and corporate site
   networks) attach to providers (e.g., regionals, commercial providers,
   and government backbones) in only one or a small number of carefully
   controlled access points.  For discussion of OSI NSAP allocation in
   this paper, providers are treated as composing a mesh having no fixed
   hierarchy.  Addressing solutions which require substantial changes or
   constraints on the current topology are not considered in this paper.

   There are two aspects of interest when discussing OSI NSAP allocation
   within the Internet.  The first is the set of administrative
   requirements for obtaining and allocating NSAP addresses; the second
   is the technical aspect of such assignments, having largely to do
   with routing, both within a routing domain (intra-domain routing) and
   between routing domains (inter-domain routing).  This paper focuses
   on the technical issues.

   The technical issues in NSAP allocation are mainly related to
   routing.  This paper assumes that CLNP will be widely deployed in the
   Internet, and that the routing of CLNP traffic will normally be based
   on the OSI end-system to intermediate system routing protocol (ES-IS)
   [10], intra-domain IS-IS protocol [14], and inter-domain routing
   protocol (IDRP) [16].  It is expected that in the future the OSI
   routing architecture will be enhanced to include support for
   multicast, resource reservation, and other advanced services.  The
   requirements for addressing for these future services is outside of
   the scope of this document.

   The guidelines provided in this paper have been the basis for initial
   deployment of CLNP in the Internet, and have proven very valuable
   both as an aid to scaling of CLNP routing, and to address
   administration.