X.25 API

[Andrew J. Schorr]

We have an X.25 application that currently runs on a Sun 
SparcStation 1, and we are considering porting it to an
RS/6000.  From looking at the specs for the AIX 3.1 X.25 API,
it appears that we will have a problem. 

The program in question is actually a line handler, and it is
communicating with other programs on the network using BSD sockets.
Under SunOS, this program uses select() to react to input on
either the X.25 circuit or the various socket connections.

Unfortunately, it appears that the X.25 interface under AIX 3.1
does not give the application an fd on which to select.
Instead, it has its own notion of counters, and the program
must use the x25_ctr_wait() routine to await an I/O event on
a list of circuits.  My question (for people who have experience
with this API, or, perhaps, those who implemented it) is how
does one intelligently multiplex X.25 I/O with I/O on normal
Unix fd's (as supplied by the socket interface)?

Thanks in advance,
Andy

P.S. I think I can use x25_ctr_test() to poll the X.25 circuits,
     but it would be nice to avoid polling.