Method and apparatus for routing internet telephone calls based upon the media types and formats or CODEC capabilities of the end points or destinations

In a packet-based communications network, where proxy servers guide the routing of requests and responses between destinations to aid in establishing the flow of voice or other media or multimedia streams between the destinations, and where at least some destinations are assigned an IP or other network address and a telephone number or other symbolic address, a system for establishing the routing of the media streams comprising:

• at least one directory database associating at least some destination network addresses with symbolic addresses and, in at least some cases, also with media type and format or CODEC capability information;
• at least one proxy server connecting to the directory database and including programs comprising:
• a first program that causes the proxy server, in response to receiving from a destination a given request which contains a symbolic address, to route the given received request to a destination whose network addresses the directory database associates with the symbolic address contained in the given received request;
• a second program, responding in at least some cases when the directory database associates two or more network addresses with the symbolic address contained in such a given received request, that causes the proxy server to route the given received request to the one of the two or more network addresses which the directory database associates with media type and format or CODEC capability information most compatible with the media type and format or CODEC capabilities of the destination that sent out the given received request, determining the media type and format or CODEC capability of the destination that sent out the given received request either by retrieving that information from the given received request or by retrieving from the directory database the media type and format or CODEC capability information that is linked to the network address of the destination that sent out the given received request, and
• a third program that establishes in the directory database associations between network addresses of at least some destinations and their media types and formats or CODEC capabilities by retrieving media type and CODEC capability information and network address information from at least some received requests or responses and then establishing linkages in the directory database consistent with this retrieved information.

In a packet-based communications network, where proxy servers guide the routing of requests and responses between destinations to aid in establishing the flow of voice or other media streams between the destinations, and where at least some destinations are assigned an IP or other network address and a telephone number or other symbolic address, a system for establishing the routing of the media streams comprising:

• directory database means for associating at least some destination network addresses with symbolic addresses and, in at least some cases, also with media type and format or CODEC capability information;
• proxy server means connecting to the directory database and including programs comprising
• first program means for receiving from a destination a given request which contains a symbolic address and for routing the given received request to a destination whose network address the directory database associates with the symbolic address contained in the given received request;
• and
• second program means for responding, in at least some cases when the directory database associates two or more network addresses with the symbolic address contained in such a given received request, to a given received request by routing the given received request to the one of the two or more network addresses which the directory database associates with media type and format or CODEC capability information most compatible with the media type and format or CODEC capabilities of the destination that sent out the given received request.

A method for establishing the routing of media streams flowing between destinations in a packet-based communications network where at least some destinations are assigned an IP or other network address and a telephone number or other symbolic address and where requests and responses must be routed between the destinations to aid them in establishing the routing of media streams, said method comprising:

• establishing a directory database;
• entering destination network addresses into the directory database and associating at least some of the network addresses with symbolic addresses and with media type and format or CODEC capability information;
• in response to receiving from a destination a given request which contains a symbolic address, routing the given received request to a destination whose network address the directory database associates with the symbolic address contained in the given received request;
• and
• if the directory database associates two or more network addresses with the symbolic address contained in such a given received request, routing the given received request to the one of the two or more network addresses which the directory database associates with media type and format or CODEC capability information most compatible with the media type and format or CODEC capabilities of the destination that sent out the given received request.