OSI/AS Configuration and Management Manual

NSAP Addressing
OSI/AS Configuration and Management Manual—424119-001
3-12
DSP Component
The maximum length of the DSP is shown in Table 3-3.
Continuing with the example used in Table 3-1
and Table 3-2, an AFI value of 39
indicates that the IDP authority is ISO DCC and the DSP syntax is binary. Table 3-3
shows that the maximum DSP length for binary ISO DCC is 14 binary octets.
Note that there is no correspondence between the different syntax types. For example, an
NSAP address in decimal digits is not interchangeable with, nor convertible to, an
NSAP address in binary octets: they are two different NSAP addresses, even if they are
governed by the same network addressing authority. However, all NSAP addresses share
in common the fact that when they are encoded for transmission, they must be less than
or equal to 20 binary octets or 40 decimal ISO 646 digits (as specified by ISO 8348,
Addendum 2).
Table 3-3. DSP Values
If the IDI Format
(Authority) Is... Maximum DSP Length Is...
Binary
Octets
Decimal*
Digits
Characters
(ISO 646)
National
Characters
X.121 (CCITT
X.121)
924
ISO DCC (ISO 3166) 14 35
F.69 (CCITT
F.69)
12 30
E.163 (CCITT
E.163)
10 26
E.164 (CCITT
E.164)
923
ISO ICD (ISO 6523) 13 34
Local 19 7
* If the AFI specifies decimal syntax for the DSP, the network addressing authority may choose a null length for
the DSP. In this case, the NSAP address consists of the IDI value plus the AFI value.