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.
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.
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.
Multiple Access Protocol over SONET/SDH (MAPOS)  is a high-speed link-layer protocol that provides multiple access capability over SONET(Synchronous Optical Network)/SDH(Synchronous Digital Hierarchy). Its frame format is based on the HDLC-like framing  for PPP. A component called "Frame Switch"  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)  datagrams are transmitted in MAPOS HDLC frames .
This document describes the protocol parameters used in MAPOS version 1 .
The MAPOS Version 1 Data Link Layer  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  0023-FCFF Not Used - reserved FE01 MAPOS Version 1 Address Resolution Protocol (ARP) FE03 MAPOS Version 1 Node Switch Protocol (NSP) FE05 MAPOS Version 1 Switch Switch Protocol (SSP) FE07-FEFF Not Used - reserved
 Murakami, K. and M. Maruyama, "MAPOS - Multiple Access Protocol over SONET/SDH, Version 1," RFC-2171, June 1997.
 CCITT Recommendation G.707: Synchronous Digital Hierarchy Bit Rates (1990).
 CCITT Recommendation G.708: Network Node Interface for Synchronous Digital Hierarchy (1990).