Abstract: A system for estimating call waiting time for a call in a queue takes into account multiple queues wherein agents are shared between queues, abandoned call history, and virtual and priority queues. The system in a preferred embodiment is a computer-telephony integration (CTI) software application adapted to execute on a CTI processor, which may be coupled to switching equipment at network level in a connection-oriented, switched telephony (COST) network or to a switch at call-center level, or both.