Cabletron Systems MMAC-Plus SFCS-1000, Руководство по настройке

Страница: 54 / 404

2-4
Configuring a Classical IP ATM Network
2.2 Address Registration and ILMI
Before a host can establish connections over a physical interface, the host
must know the NSAP address for that interface. The primary purpose of
Interim Local Management Interface (ILMI) is to discover and register these
NSAP addresses dynamically.
2.2.1 NSAP Addresses
For private ATM networks, addresses uniquely identify ATM endpoints. The
UNI 3.0 address format is modeled after that of an OSI Network Service
Access Point, hence the name NSAP address.
Three address formats have been specified: DCC, ICD, and E.164. Cabletron
implements the ICD ATM format. Per the UNI 3.0 specification, all private
networks should accept initial call set-up messages containing ATM
addresses with any of the approved formats and forward the calls as neces-
sary.
An NSAP address consists of the following:
• a 13-byte network-side prefix - The prefix is the NSAP prefix of the
SCP to which the host is attached.
• a seven-byte user-side part - This consists of the following:
- a six-byte End System Identifier (ESI) - The ESI is the unique IEEE
MAC address of the interface.
- a one-byte selector - Although each Classical IP interface for a
given physical interface uses the same prefix and ESI, the selector
field is the part that indicates the number of the specific Classical
IP interface. The selector field is 00 for qaa0, 01 for qaa1, 02 for
qaa2, and 03 for qaa3.