Patent ID: 8301796

Claim:
A computer storage medium comprising program instructions that when executed by data processing apparatus cause the data processing apparatus to perform operations comprising: at a client system, establishing a communication session to receive a media stream from a server system; receiving through the communication session, as part of the media stream, values of parameters relating to a sub media stream, the values included in a header portion of a first real-time, priority-based network communication of the communication session; storing the values of the parameters at the client system; receiving through the communication session, as part of the media stream from the server system, state information and a data payload, the state information being included in a control portion of a second real-time, priority-based network communication of the communication session, and the data payload being included in the second real-time, priority-based network communication; determining, from the state information, a purpose of the second real-time, priority-based network communication in relation to the media stream from the server system in accordance with whether a header portion of the second real-time, priority-based network communication includes, either, only one or more new values corresponding to one or more of the parameters, or no values corresponding to the parameters; updating, when the second header portion includes the one or more new values, one or more of the stored values based, at least in part, on the one or more new values; and processing the data payload based at least in part on the determined purpose and the stored values of the parameters.