2.3.13.5 Life Cycle of calls

All of the operations that start the lifetime of a call result in the TAPI DLL and Service Provider exchanging identifiers for the new call. In the case of the TAPI DLL originated calls, the TAPI DLL passes its identifier and receives the Service Provider's identifier as a return parameter. In the case where the call originates in the Service Provider, the Service Provider passes its identifier to the TAPI DLL and receives the TAPI DLL's identifier as a return parameter.