If you have multiple links, 
.L x25mgr 
listens on all links, unless you specify a link with this parameter.
.IP "\fLpid cc \fR(mandatory)"
The first four bytes of the Call User Data field in an incoming Call
Request.  
The value \fLcc\fP is the pid recommended by RFC 877 to identify IP/X.25
connections.
.L x25mgr 
uses this value to accept (or not accept) incoming calls.
This value is used to distinguish between IP/X.25 and other X.25 uses.
.IP "\fLlocal_x121 \fI<X.121_address>\fR (optional)"
Normally,
.L x25mgr
listens on all links for any incoming X.121 address.
If you specify this parameter, 
it should exactly match the contents of the called address field
in an Incoming Call packet.
