Under the present invention, resources such as gateways which interconnect usually disparate networks are released for processes which, while originally being inter-network, become intra-network, and the resource (e.g., gateway) is no longer needed for the intra-network process to be completed. The present invention is useful to optimally interwork an IP network with a PISN employing the QSIG Call Diversion and Single Step Call Transfer supplementary services. Attendant features achieved with implementation of the present invention, include quick release of network circuits that are being used for media connections that are no longer necessary and of system resources that are being used for signaling connections that are no longer necessary. Under the present invention, a media channel is not established from an IP network to a PISN, if a user of the PISN makes a call to a user of the IP network, who has forwarded/diverted her calls into the PISN and vice versa.