Distributed processing of high level protocols, in a network access server

A method for routing data between a host connected to a computer network and a remote user connected to said host via a telephone line, the data associated with a higher level protocol for allowing the host to communicate with the remote user, said higher level protocol comprising a real-time protocol associated with voice, video, and data communication, the method performed in a communications access system comprising a telephone line interface connected to said telephone line, a plurality of modems, each modem associated with a modem computing platform, and a network interface having a gateway computing platform, comprising the steps of:

• receiving said data destined for said remote user and directing said data from said network interface to one of said modems in said communications access system;
• distributing the processing of said higher level protocol for said data, such that said gateway computing platform performs a first portion of the processing of said higher level protocol and said modem computing platform in said modem performs a second portion of the processing of said higher level protocol;
• and
• subsequently directing the data from said modem computing platform through said telephone line interface onto said telephone line for transmission to said remote user.

In a network access server for providing connectivity between a host source of digital data connected to a network and a remote terminal connected to the public switched telephone network, comprising, in combination a telephone line interface operatively connecting said network access server to a telephone line carrying digital telephone signals;

• a plurality of DSP computing platforms for demodulating inbound telephone signals and modulating outbound telephone signals for transmission on said telephone line to said remote terminal;
• a bus passing digital telephone signals from said telephone line interface to said DSP computing platforms;
• and a network interface receiving data from said modems via a bus and routing said data onto said network;
• the improvement comprising:
• said network interface comprising a computing platform processing a higher level protocol associated with communication between said remote terminal and said host on said network, said higher level protocol selected from the group of protocols consisting of the Point-to-Point Protocol and the Serial Line Interface Protocol, and wherein each of said plurality of DSP computing platforms performs the processing of a subset of functions associated with said higher level protocol associated with said communication.

In a network access server for providing connectivity between a host source of digital data connected to a network and a remote terminal connected to the public switched telephone network, comprising, in combination a telephone line interface operatively connecting said network access server to a telephone line carrying digital telephone signals;

• a plurality of DSP computing platforms for demodulating inbound telephone signals and modulating outbound telephone signals for transmission on said telephone line to said remote terminal;
• a bus passing digital telephone signals from said telephone line interface to said DSP computing platforms;
• and a network interface receiving data from said modems via a bus and routing said data onto said network;
• the improvement comprising:
• said network interface comprising a computing platform processing a higher level protocol associated with communication between said remote terminal and said host on said network, wherein said higher level protocol comprises a Real-time Transport Protocol (RTP), and wherein said plurality of DSP computing platforms performs the processing of a subset of functions associated with said higher level protocol.

A method of performing the processing of the Real-time Transport Protocol (RTP) protocol in a communication session from a source connected to a computer network and a destination connected to a telephone line, the method performed in a network access server, comprising the steps of:

• passing RTP frames of data for said session from a gateway computing platform in said network access server having a network interface to a modem in said network access server;
• performing jitter buffering for said RTP frames of data in a computing platform in said modem;
• converting said RTP frames of data into a form suitable for transmission on said telephone line;
• and
• subsequently directing said data on said telephone line from said network access server to said destination.