Network telephony appliance and system for inter/intranet telephony

A network appliance is provided having a network controller subsystem for coupling the appliance to a data network for providing and receiving data packets to and from a packet data network. A digital signal processing subsystem is coupled to the network controller subsystem. A signal conversion subsystem is coupled to the digital signal processing subsystem and a user interface subsystem is coupled to both the signal conversion subsystem and the digital signal processing subsystem. The digital signal processing subsystem operates under the control of a computer program which is capable of detecting incoming calls, initiating call sessions, and preferably, implementing advanced telephony features.