A universal or multi-purpose network server having enhanced processing functions which are performed in association with a telecommunicatons network to provide multi-mode communications via a combination of the public switched telephone network (PSTN) and a public packet data network, such as the Internet. The improved network server includes a multiplicity of application processing units optimized for the processing of specific signal types. The type of signals being handled by the server is ascertained by means of a passive monitor and each type of signal is switched to an application processor on the basis of the signal type identified by the passive monitor. The processor places the processed signal in the protocol of the public packet data network and delivers that signal to a router connected to the public packet data network. Provision is made for establishing the availability of a called party through a control network before establishing an end to end communication link.