OSI/AS Configuration and Management Manual

NSAP Addressing
OSI/AS Configuration and Management Manual—424119-001
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Notational Format for Encoded NSAP Addresses
that use the national character set, the network addressing authority must define and
publish the binary encoding rules to be used by the Network Layer protocols.
Notational Format for Encoded NSAP Addresses
HRPF (hexadecimal reference publication format) is the designated notational format
used in written and verbal communication to convey encoded NSAP addresses. Using
this format, an NSAP address is expressed as a slash (/) followed by a string of
hexadecimal digits (up to 40 maximum), where each digit represents a half-octet of the
encoded address.
How OSI/TS Handles NSAP Addresses
The OSI/TS subsystem uses HRPF without the “/” for all NSAP address parameters in
SCF commands and the application interface. This format enables the OSI/TS
subsystem to handle all NSAP addresses in the same way, regardless of any locally
chosen semantics and syntax.
The Network Layer in OSI/TS does not perform the encoding described in Step 2:
Encoding Network Layer Protocols on this page. Instead, it uses a simple conversion
algorithm to convert HRPF-encoded NSAP addresses to NPDU address information.
Nonstandard NSAP Address Representation
In networks that include systems from manufacturers other than Compaq, some systems
may locally employ nonstandard, vendor-specific representations of DSP values (for
example, ASCII). In a similar manner, an administrator of a network addressing domain
may choose to use nonstandard representations of DSP values within that domain. In all
such cases, a programmatic algorithm for converting nonstandard NSAP addresses to
HRPF format, and vice versa, must be provided.
Examples of NSAP Addresses
The following three examples show different types of NSAP addresses and explain the
components of each address:
•
Example 1: ISO DCC and Binary Syntax DSP on this page
•
Example 2: Locally Defined and Binary Syntax DSP on page 3-15
•
Example 3: Locally Defined and ISO 646 DSP on page 3-17
Example 1: ISO DCC and Binary Syntax DSP
Figure 3-4 shows the first example NSAP address and its components.