Installing and Administering OSI Transport Services

56 Chapter 1
HP OTS/9000 Resources
Current NSAP Allocation Formats
The United States GOSIP format, whose administration authority is
NIST, is to be used by United States Government agencies for their OSI
networks. NIST will also assign NSAPs from their NSAP space to
non-government organizations upon request.
This format is a good example of how the various PAP fields may be used
to create a well defined NSAP space that can evolve over time. U.S.
GOSIP has taken a domain/area approach to routing and has defined the
entire structure of the DSP. Because of this, they have also added some
fields that will allow their structure to change over time, namely the DFI
and Rsv fields.
To obtain more information about the U.S. GOSIP NSAP structure,
contact:
DFI DSP Format Identifier. This is used to specify the
structure, semantics and administration
requirements for the remainder of the DSP.
Currently, only one DSP Format exists. This field is
similar in function to a Version field.
Admin This field functions in much the same way as the
Org ID field in the ANSI format. It is an
Administration authority identifier. The values for
this field are under the control of NIST.
Rsv Two octets are reserved for future expansion.
Domain The Routing Domain this NSAP resides in. Routing
Domain values are determined by the authority
identified by the Admin field.
Area The Area number this NSAP resides in. Area values
are determined by the authority identified by the
Admin field.
ES A number, unique within the area, that identifies the
end system. End System identifiers are determined
by the network administrator
NSel This field identifies the Network Service user. U.S.
GOSIP recommends this value be set to 01 for the
Transport protocol.