HP X.25/9000 Programmer's Guide
16 Chapter2
X.25 Addressing
Addressing Options for Servers
NOTE If any of the three tests fail the call is cleared before reaching the socket,
and the server application (above the socket) will never know anything
about the incoming call request.
The matching tests for incoming calls and how a server controls calls are
described below.
Call-matching by X.25 Interface Name
The name of an X.25 interface is assigned during configuration. Refer to
the X.25/9000 User’s Guide for details on the interface name.
The
x25ifname[]
field of the x25addrstr structure can contain an
interface name to designate a particular X.25 interface to be used for call
connection. It can also specify that calls be connected from any X.25
interface on the system. If your application will receive calls from a
single interface, the name must be specified in the
x25ifname
field. If
your application will receive calls arriving over any interface, do not
specify the interface name in the
x25ifname[]
field (set the field to the
null string “\0” and the
25hostlen
field to 0).
The
x25ifname[]
field is not relevant when only one X.25 interface is in
use. If more than one interface is in use, specify which interface connects
to the network in the
x25ifname[]
field.
To accept calls from more than one X.25 interface but not all interfaces,
you must create a separate socket for each interfaces from which calls
will be accepted.The resulting listen() sockets must be monitored with
the select() call to determine when a matching incoming call arrives.
Refer to “Using Nonblocking I/O” in Chapter 4 , “Sending and Receiving
Data,” of this manual.
Call-matching by Called X.121 Address
The X.121 address for an X.25 interface is assigned during initialization.
When an X.25 interface is connected to a PSN, the X.121 address is
assigned to the interface by the network provider. The X.121 address is a
string of decimal digits (0 – 9). Refer to the X.25/9000 User’s Guide for
details on X.121 address initialization.
When an interface is connected to a PSN, only CALL REQUEST packets
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