Browse Prior Art Database

The Cisco SRP MAC Layer Protocol (RFC2892)

IP.com Disclosure Number: IPCOM000005011D
Original Publication Date: 2000-Aug-01
Included in the Prior Art Database: 2001-Jul-13

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

D. Tsiang: AUTHOR [+2]

Abstract

This document specifies the MAC layer protocol, "Spatial Reuse Protocol" (SRP) for use with ring based media. This is a second version of the protocol (V2).

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 4% of the total text.

Network Working Group D. Tsiang Request for Comments: 2892 G. Suwala Category: Informational Cisco Systems

August 2000

The Cisco SRP MAC Layer Protocol

Status of this Memo

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

Copyright Notice

Copyright (C) The Internet Society (2000). All Rights Reserved.

Abstract

This document specifies the MAC layer protocol, "Spatial Reuse Protocol" (SRP) for use with ring based media. This is a second version of the protocol (V2).

The primary requirements for SRP are as follows:

Efficient use of bandwidth using: spatial reuse of bandwidth local reuse of bandwidth

minimal protocol overhead Support for priority traffic Scalability across a large number of nodes or stations attached to

a ring "Plug and play" design without a software based station management transfer (SMT) protocol or ring master negotiation as seen in

other ring based MAC protocols [1][2] Fairness among nodes using the ring Support for ring based redundancy (error detection, ring wrap,

etc.) similar to that found in SONET BLSR specifications. Independence of physical layer (layer 1) media type.

This document defines the terminology used with SRP, packet formats, the protocol format, protocol operation and associated protocol finite state machines.

Tsiang Suwala Informational [Page 1]

RFC 2892 The Cisco SRP MAC Layer Protocol August 2000

Table of Contents

1. Differences between SRP V1 and V2 ....................... 3 2. Terms and Taxonomy ...................................... 4 2.1. Ring Terminology .................................. 4 2.2. Spatial Reuse ..................................... 5 2.3. Fairness .......................................... 6

2.4. Transit Buffer .................................... 7 3. SRP Overview ............................................ 8 3.1. Receive Operation Overview ........................ 8 3.2. Transmit Operation Overview ....................... 8 3.3. SRP Fairness Algorithm (SRP-fa) Overview .......... 9 3.4. Intelligent Protection Switching (IPS) Protocol

Overview .......................................... 9 4. Packet Formats .......................................... 13 4.1. Overall Packet Format ............................. 13 4.2. Generic Packet Header Format ...................... 14 4.2.1. Time To Live (TTL) ......................... 14 4.2.2. Ring Identifier (R) ........................ 15 4.2.3. Priority Field (PRI) ....................... 15 4.2.4. MODE ....................................... 15 4.2.5. Parity Bit (P-bit) ......................... 16 4.2.6. Destination Address ........................ 16 4.2.7. Source Address ............................. 16

4.2.8. Protocol Type .............................. 16 4.3. SRP Cell For...