A MAPOS version 1 Extension - Switch-Switch Protocol (RFC2174)
Original Publication Date: 1997-Jun-01
Included in the Prior Art Database: 2019-Feb-15
Internet Society Requests For Comment (RFCs)
K. Murakami: AUTHOR [+1]
This memo documents a MAPOS (Multiple Access Protocol over SONET/SDH) version 1 extension, Switch Switch Protocol which provides dynamic routing for unicast, broadcast, and multicast. This memo provides information for the Internet community. This memo does not specify an Internet standard of any kind.
Network Working Group K. Murakami Request for Comments: 2174 M. Maruyama Category: Informational NTT Laboratories June 1997
A MAPOS version 1 Extension - Switch-Switch Protocol
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 a MAPOS (Multiple Access Protocol over SONET/SDH) version 1 extension, Switch Switch Protocol which provides dynamic routing for unicast, broadcast, and multicast. 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 a MAPOS version 1 extension, SSP (Switch Switch Protocol). MAPOS is a multiple access protocol for transmission of network-protocol packets, encapsulated in High-Level Data Link Control (HDLC) frames, over SONET/SDH. In MAPOS network, a SONET switch provides the multiple access capability to end nodes. SSP is a protocol of Distance Vector family and provides unicast and broadcast/multicast routing for multiple SONET switch environment.
This document describes an extension to MAPOS version 1, Switch Switch Protocol, for routing both unicast and broadcast/multicast frames. MAPOS, Multiple Access Protocol over SONET (Synchronous Optical Network) / SDH (Synchronous Digital Hierarchy) , is a link layer protocol for transmission of HDLC frames over SONET/SDH. A SONET switch provides the multiple access capability to each node. SSP is a dynamic routing protocol designed for an environment where a MAPOS network segment spans over multiple switches. It is a protocol of Distance Vector family. It provides both unicast and broadcast/multicast routing. First, this document describes the outline of SSP. Next, it explains unicast and broadcast/multicast routing algorithms. Then, it describes the SSP protocol in detail.
Murakami & Maruyama Informational [Page 1]
RFC 2174 MAPOS June 1997
2. Constraints in Designing SSP
SSP is a unified routing protocol supporting both unicast and broadcast/multicast. The former and the latter are based on the Distance Vector  and the spanning tree algorithm, respectively. In MAPOS version 1, a small number of switches is assumed in a segment. Thus, unlike DVMRP(Distance Vector Multicast Routing Protocol), TRPB(Truncated Reverse Path Broadcasting) is not supported for simplicity. This means that multicast frames are treated just the same as broadcast frames and are delivered to every node.
In MAPOS version 1, there are two constraints regarding design of the broadcast/multicast routing algorithm;
(1) there is no source address field in MAPOS HDLC frames
(2) there is no TTL(Time To Live) field in MAPOS HDLC frames to prevent forwarding loop.
To cope with the first issue, VRPB(Virtual Reverse P...