The Generic Call Control Service (GCCS) provides the basic call control service for the API. It is based around a third party model, which allows calls to be instantiated from the network and routed through the network.
The GCCS supports enough functionality to allow call routing and call management for today's Intelligent Network
(IN) services in the case of a switched telephony network, or equivalent for packet based networks.
It is the intention of the GCCS that it could be readily specialised into call control specifications, for example, ITU-T Recommendations H.323, Q.763 ISUP, Q.931 and Q.2931, ATM Forum specification UNI3.1 and RFC 3261 Session Initiation Protocol, or any other call control technology.
For the generic call control service, only a subset of the call model defined in clause 4 is used; the API for generic call control does not give explicit access to the legs and the media channels. This is provided by the Multi-Party Call Control Service. Furthermore, the generic call is restricted to two party calls, i.e. only two legs are active at any given time. Active is defined here as 'being routed' or connected.
The GCCS is represented by the IpCallControlManager
interfaces that interface to services provided by the network. Some methods are asynchronous, in that they do not lock a thread into waiting whilst a transaction performs.
In this way, the client machine can handle many more calls, than one that uses synchronous message calls. To handle responses and reports, the developer must implement IpAppCallControlManager
to provide the callback mechanism.