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A MAPOS version 1 Extension - Node Switch Protocol (RFC2173)

IP.com Disclosure Number: IPCOM000002731D
Original Publication Date: 1997-Jun-01
Included in the Prior Art Database: 2000-Sep-13
Document File: 5 page(s) / 11K

Publishing Venue

Internet Society Requests For Comment (RFCs)

Related People

K. Murakami: AUTHOR [+2]

Abstract

This document describes a MAPOS extension, Node Switch Protocol, for automatic node address assignment. MAPOS is a multiple access protocol for transmission of network-protocol datagrams, encapsulated in High-Level Data Link Control (HDLC) frames, over SONET/SDH. NSP automates the HDLC address configuration of each node. Using NSP, a node retrieves its HDLC address from the switch to which it is connected.

This text was extracted from a ASCII document.
This is the abbreviated version, containing approximately 24% of the total text.

Network Working Group K. Murakami

Request for Comments: 2173 M. Maruyama

Category: Informational NTT Laboratories

June 1997

A MAPOS version 1 Extension - Node 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.

Abstract

This document describes a MAPOS extension, Node Switch Protocol, for

automatic node address assignment. MAPOS is a multiple access

protocol for transmission of network-protocol datagrams, encapsulated

in High-Level Data Link Control (HDLC) frames, over SONET/SDH. NSP

automates the HDLC address configuration of each node. Using NSP, a

node retrieves its HDLC address from the switch to which it is

connected.

1. Introduction

MAPOS[1], Multiple Access Protocol over SONET(Synchronous Optical

Network)/SDH(Synchronous Digital Hierarchy)[2][3][4][5], is a

protocol for transmission of HDLC frames over SONET/SDH. A SONET

switch provides multiple access capability to each node. In MAPOS,

each node has a unique HDLC address within a switch. The address is

equivalent to the port number of the switch to which the node is

connected. This document describes an extension to MAPOS, Node

Switch Protocol, which enable automatic HDLC address assignment.

First, it explains the addressing of MAPOS. Then, it describes the

NSP protocol for automatic HDLC node address assignment.

2. Node Address Format

This section describes MAPOS Version 1 address format in single and

multiple switch environment.

2.1 Address Format

In MAPOS network, each end node has a unique HDLC address. As shown

in Figure 1, the address length is 8 bits. The LSB is always 1 which

indicates the end of the field. When a SONET switch receives an HDLC

frame, it forwards the frame based on the address in the frame

header.

In unicast, MSB is 0 and the rest of the bits are the port number to

which a node is connected. Since the LSB is always 1, the minimum and

maximum addresses are 0x01 and 0x7F, respectively. Address 0x01 is

reserved and is assigned to the control processor in a SONET switch.

In broadcast, MSB is 1 and the rest of the bits are all 1s. In

multicast, MSB is 1 and the rest of the bits, except for the LSB,

indicate the group address.

+-------------+-+

| | | | | | | | |

| |port number|1|

+-+--------...