Call transfer using session initiation protocol (SIP)

A system is provided for providing communication event routing and transfer capability in a multi-site communication-center environment. The system utilizes a presence protocol application and a routing application for determining availability of an agent or system and for setting up the transfer from a point of transfer on a network to a destination of transfer on the same or connected network. In a preferred use the presence protocol application is shared by communication-center sites cooperating in the transfer and routing of events and the presence protocol enables at least one event-handling process normally performed by the routing application.