Abstract: A call management messaging system enables the integration of the Internet with the Public Switched Telephone Network PSTN in a manner such that systems, services, and devices on either can communicate with systems, services, and devices on the other. The full benefit and unique characteristics of either network are thereby made available to these communications. Call management messages include call setup requests, call acceptance, call rejection for busy, call forwarding, and similar messages necessary for creating and disconnecting voice and multimedia communications across the PSTN or the Internet. Devices on both the Internet and the PSTN have messaging addresses, and are associated with the call management messaging system. A device creates an Internet communication with another device by dialing its telephone number.