Abstract: A multi-domain telephony application programming interface is disclosed for managing a multimedia call across a plurality of domains. Advanced addressing techniques are utilized to support a media independent call control model across multiple communication domains in a consistent and integrated manner. In an illustrative embodiment, the multi-domain telephony application programming interface is based on the Java Telephony API (JTAPI). The multi-domain telephony application programming interface recognizes a call between two domains as one call on both systems, and presents the calls together as a single transaction to a user application. The multi-domain telephony application programming interface identifies and manages a set of inter-domain addresses that are the egress and access points between two domains, so that calls can traverse between them.