[Asterisk-Users] isdn out of band signalling

[James Harper]

This is more an isdn question than an asterisk specific one, but is
there any end to end signalling channel available during call setup? Eg
if AParty dials BParty, can any information be conveyed (in both
directions preferably, and in addition to CLI[PR]) before the call is
answered?

The only way I can think of doing this is for the AParty to use CLIP to
present a different number to the BParty, and for the BParty to
terminate the call while ringing after a certain time (the time taken to
terminate forms the information from B to A).

Thanks

James