OSI/TS Configuration and Management Manual

OSI/TS Configuration and Management Manual—424831-001
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Background Information About
Addressing
This section provides background information about NSAP addressing and OSI/TS
subdevice addressing needed when configuring an OSI/TS subsystem.
This section is intended for anyone who must construct an NSAP address, use an NSAP
address in a command, or write an application that uses OSI/TS. If you are already
familiar with how NSAP addresses are constructed, how network addressing authorities
and domains work, and how OSI/TS subdevices work, then you do not need to read this
section.
An NSAP address is the global, network unique address of an end system NSAP.
Correct NSAP addressing, therefore, is crucial to proper network configuration.
However, NSAP addresses can be complicated, and costly mistakes can be made when
configuring them. A thorough understanding of NSAP addressing schemes is
particularly important for customers who are implementing OSI networks in which
Compaq products communicate with products supplied by other vendors.
This section includes the following topics that apply to all OSI addresses (in other
words, this is general information that applies to OSI products from all vendors):
•
SNPA addresses
•
LSAP selectors
•
NSAP addresses
•
Structure of NSAP addresses
•
Converting NSAP addresses
•
Examples of NSAP addresses
•
Suggestions for network addressing administrators
The following topic applies to OSI/TS only (subdevices are a Compaq implementation
and are not part of the ISO standards):
•
OSI/TS subdevices
SNPA Addresses
An SNPA (subnetwork point of attachment) address is the address of an end system or
intermediate system. It is the address through which subnetwork service is made
available to the Network Layer. What an SNPA address actually means depends on
whether it refers to a LAN or an X.25 WAN, as discussed in the following subsections.