Abstract: This invention concerns an autonomus media termination centric signaling architecture that takes advantage of both a peer-to-peer signaling protocol such as the SIP and Master/Slave protocols such as MGCP/Megaco/NCS. More specifically, the present invention describes an Internet telephony agent comprising a user agent call manager including a user agent stack for communication with a peer, a master stack, and a multi-protocol call manager for communication between the user agent stack and the master stack; and a media termination coupled to the user agent call manager including a hardware manager, and a slave stack for communication between the master stack and the hardware manager. The user call manager and the media termination of Internet telephony agent may be tightly coupled or loosely coupled, allowing the inter-operation of the Internet telephony agent with both SIP and MGCP/Megaco/NCS media terminations.