A MAPOS version 1 Extension - Node Switch Protocol (RFC2173)
Original Publication Date: 1997-Jun-01
Included in the Prior Art Database: 2000-Sep-13
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.
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|
+-+--------...