Network Working Group                                        M. Maruyama
Request for Comments: 2172                                   K. Murakami
Category: Informational                                 NTT Laboratories
                                                               June 1997


                    MAPOS Version 1 Assigned Numbers


Status of this Memo

   This memo provides information for the Internet community.  This memo
   does not specify an Internet standard of any kind.  Distribution of
   this memo is unlimited.

Authors' Note

   This memo documents the parameters used in the Multiple Access
   Protocol over SONET/SDH Version 1.  This document is NOT the product
   of an IETF working group nor is it a standards track document.  It
   has not necessarily benefited from the widespread and in-depth
   community review that standards track documents receive.

Abstract

   This document describes the protocol parameters used in the Multiple
   Access Over SONET/SDH (MAPOS) version 1. MAPOS is a link layer
   protocol and provides multiple access capability over SONET/SDH
   links.

1. Introduction

   Multiple Access Protocol over SONET/SDH (MAPOS) [1] is a high-speed
   link-layer protocol that provides multiple access capability over
   SONET(Synchronous Optical Network)/SDH(Synchronous Digital
   Hierarchy)[2][3][4][5]. Its frame format is based on the HDLC-like
   framing [6] for PPP.  A component called "Frame Switch" [1] allows
   multiple nodes to be connected together in a star topology to form a
   LAN. Using long haul SONET/SDH links, the nodes on such a "SONET-LAN"
   can span over a wide geographical area. The Internet Protocol (IP)
   [7] datagrams are transmitted in MAPOS HDLC frames [8].

   This document describes the protocol parameters used in MAPOS version
   1 [1].







Maruyama &  Murakami         Informational                      [Page 1]

RFC 2172                         MAPOS                         June 1997


2. Protocol Field Assignments

   The MAPOS Version 1 Data Link Layer [1] contains a 16 bit Protocol
   field to identify the the encapsulated protocol.  The Protocol field
   is consistent with the ISO 3309 (HDLC) extension mechanism for
   address fields.  All protocol numbers MUST be assigned such that the
   least significant bit of the most significant octet equals "0", and
   the least significant bit of the least significant octet equals "1".

   Assigned MAPOS Protocol Numbers

      Value (in hex)  Protocol Name

      0001-001F       Not Used - reserved
      0021            MAPOS Version 1 Internet Protocol Version 4 [8]
      0023-FCFF       Not Used - reserved
      FE01            MAPOS Version 1 Address Resolution Protocol (ARP[8])
      FE03            MAPOS Version 1 Node Switch Protocol (NSP[9])
      FE05            MAPOS Version 1 Switch Switch Protocol (SSP[10])
      FE07-FEFF       Not Used - reserved


References

   [1]   Murakami, K. and M. Maruyama, "MAPOS - Multiple Access Protocol
         over SONET/SDH, Version 1," RFC-2171, June 1997.

   [2]   CCITT Recommendation G.707: Synchronous Digital Hierarchy Bit
         Rates (1990).

   [3]   CCITT Recommendation G.708: Network Node Interface for
         Synchronous Digital Hierarchy (1990).

   [4]   CCITT Recommendation G.709: Synchronous Multiplexing Structure
         (1990).

   [5]   American National Standard for Telecommunications - Digital
         Hierarchy - Optical Interface Rates and Formats Specification,
         ANSI T1.105-1991.

   [6]   Simpson, W., editor, "PPP in HDLC-like Framing," RFC-1662,
         July 1994.

   [7]   Postel, J., "Internet Protocol (IP)," RFC-791, September 1981.

   [8]   Murakami, K. and M. Maruyama, "IPv4 over MAPOS Version 1,"
         RFC-2176, June, 1997.




Maruyama &  Murakami         Informational                      [Page 2]

RFC 2172                         MAPOS                         June 1997


   [9]   Murakami, K. and M. Maruyama, "A MAPOS version 1 Extension -
         Node Switch Protocol," RFC-2173, June, 1997.

   [10]  Murakami, K. and M. Maruyama, "A MAPOS version 1 Extension -
         Switch Switch Protocol," RFC-2174, June, 1997.

Acknowledgements

   The authors would like to acknowledge the contributions and
   thoughtful suggestions of John P. Mullaney, Clark Bremer, Masayuki
   Kobayashi, Paul Francis, Toshiaki Yoshida, and Takahiro Sajima.

Author's Address

     Mitsuru Maruyama
     NTT Software Laboratories
     3-9-11, Midori-cho
     Musashino-shi
     Tokyo-180, Japan
     E-mail: mitsuru@ntt-20.ecl.net

     Ken Murakami
     NTT Software Laboratories
     3-9-11, Midori-cho
     Musashino-shi
     Tokyo-180, Japan
     E-mail: murakami@ntt-20.ecl.net
























Maruyama &  Murakami         Informational                      [Page 3]