This seems implementable and decent, but ideally I want the ICS to ask for the code and decide whether the call can go out or not.
In other words the IPS lets all calls out to the ICS, and when they arrive to the ICS, it will handle it just as though a station would be making the call: checks its RSC and allows the call or asks for an auth code, and if the RSC of the auth code allows, then lets the call go out to telco. This would require though that calls coming in to the ICS from the IPS get some RSC assigned to them somehow to begin with.
I wanna do it this way as the ICS is talking to an OAI application that constantly updates the auth codes based on financial balance from a call-accounting system. And so if I had to make the IPS make decisions, I wouldn't know how to link that to the same OAI database to automatically update the codes.