Media over TCP

The Oracle® Enterprise Session Border Controller now supports RFC 4145 (TCP-Based Media Transport in the SDP), also called TCP Bearer support. Media over TCP can be used to support applications that use TCP for bearer path transport.

RFC 4145 adds two new attributes, setup and connection, to SDP messages. The setup attribute indicates which end of the TCP connection should initiate the connection. The connection attribute indicates whether an existing TCP connection should be used or if a new TCP connection should be setup during re-negotiation. RFC 4145 follows the offer/answer model specified in RFC3264. An example of the SDP offer message from the end point 192.0.2.2 as per RFC4145 is as given below:

           m=image 54111 TCP t38
           c=IN IP4 192.0.2.2
           a=setup:passive
           a=connection:new

This offer message indicates the availability of t38 fax session at port 54111 which runs over TCP. Oracle® Enterprise Session Border Controller does not take an active part in the application-layer communication between each endpoint.

The Oracle® Enterprise Session Border Controller provides the means to set up the end-to-end TCP flow by creating the TCP/IP path based on the information learned in the SDP offer/answer process.