OSI/TS Configuration and Management Manual

Background Information About Addressing
OSI/TS Configuration and Management Manual—424831-001
2-13
Nonstandard NSAP Address Representation
The Network Layer in OSI/TS does not perform the encoding Step 2 described earlier.
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
Figure 2-4 shows the first example NSAP address and its components.
The AFI in this example, as in those previous, is 39. Once again, Table 2-1
shows that
an AFI value of 39 identifies the IDI format as ISO DCC and the DSP syntax type as
binary.
Table 2-2
shows that the ISO DCC format, as defined by ISO 3166, identifies the
domain (the IDI) as the data country code (in this case, 999), and specifies a three-digit
IDI length. In this example, lets assume that 999 is the code for country “X.”
The DSP is the rest of the address. Table 2-3
shows that the binary DSP syntax for the
ISO DCC format can have a maximum of 14 octets; this example has the maximum
Figure 2-4. NSAP Address Example 1
204CDT .CDD
NSAP Address
/399990100000000FF0008008E0002E301
AFI IDI DSP