The TOPS Architecture for Signaling, Directory Services and Transport for Packet Telephony

Packet telephony is of increasing interest in both the telecommunications and Internet communities. The emergence of packet telephony will create new services, and presents an opportunity to rethink how conventional telephony services are implemented. We present an architecture for Telephony Over Packet networkS (TOPS). TOPS allows users to move between terminals or to use mobile terminals and be reachable by the same name. TOPS users can have multiple terminals and control how calls are routed to them. TOPS allows terminals with a range of capabilities such as video, whiteboard and allows a variety of coding formats. TOPS retains the necessary information on terminal capabilities to establish appropriate communication with the remote terminal. The architecture assumes that the underlying network supports end-to-end connectivity between terminals, with an appropriate quality of service. The components of TOPS are a directory service, an application layer signaling protocol and a logical channel