Accelerated session establishment in a multimedia gateway

1. A method of establishing a reduced setup time session between a first SIP-like terminal and a second SIP-like terminal, the session being conducted between the first SIP-like terminal and the second SIP-like terminal through a gateway, the method comprising:

receiving a first call setup message transmitted from the first SIP-like terminal to the gateway, wherein the first call setup message includes a first capability message;

transmitting a second call setup message from the gateway to the second SIP-like terminal;

receiving a second capability message transmitted from the second SIP-like terminal to the gateway;

transmitting a first capability response message from the gateway to the first SIP-like terminal;

transmitting a second capability response message from the gateway to the second SIP-like terminal;

receiving a media stream transmitted from the second SIP-like terminal to the gateway;

processing media stream, wherein processing the media stream comprises identifying a temporal feature in the media stream that enables a decoder to establish a decoder refresh point;

receiving an acknowledgment message transmitted from the first SIP-like terminal to the gateway, wherein the acknowledgement message is received at the gateway after transmitting the second capability response message; and

thereafter, transmitting the processed media stream from the gateway to the first SIP-like terminal.

2. The method of claim 1 wherein the first capability message comprises an SDP-like message.

3. The method of claim 1 wherein the second call setup message includes a second capability message.

4. The method of claim 1 wherein the second call setup message comprises an empty INVITE.

5. The method of claim 1 further comprising:

receiving a second media stream transmitted from the first SIP-like terminal to the gateway; and

transmitting the second media stream from the gateway to the second SIP-like terminal.

6. The method of claim 1 wherein transmitting the first capability response message to the first SIP-like terminal is performed after receiving the second capability message transmitted from the second SIP-like terminal to the gateway.

7. The method of claim 1 wherein a number of video capabilities in the first capability response message is less than a number of video capabilities in the first capability message.

8. The method of claim 7 wherein the number of video capabilities in the first capability response message is one.

9. The method of claim 1 wherein a number of audio capabilities in the first capability response message is less than a number of audio capabilities in the first capability message.

10. The method of claim 9 wherein the number of audio capabilities in the first capability response message is one.

11. The method of claim 1 wherein the temporal feature comprises an intra-coded frame.

12. The method of claim 1 further comprising generating a VideoFastUpdate-like message and transmitting the VideoFastUpdate-like message from the gateway to the second terminal.

13. The method of claim 1 wherein processing further comprises generating an intra-coded frame.

14. The method of claim 13 wherein generating the intra-coded frame comprises converting an inter-coded frame into an intra-coded frame.

15. The method of claim 1 wherein receiving an acknowledgment message transmitted from the first SIP-like terminal to the gateway is performed independent of receiving the media stream transmitted from the second SIP-like terminal to the gateway.

16. A method of establishing a reduced setup time session between a first SIP-like terminal and a second SIP-like terminal, the session being conducted through a gateway, the method comprising:

performing a first session setup process between the first terminal and the gateway, wherein performing the first session setup process comprises:

receiving a first INVITE message transmitted from the first SIP-like terminal to the gateway, wherein the first INVITE message includes a first capabilities message;

processing the first capabilities message;

transmitting a first capabilities response message from the gateway to the first SIP-like terminal; and

receiving an acknowledgment message transmitted from the first SIP-like terminal to the gateway;

performing a second session setup process between the second terminal and the gateway, the second session setup process being performed independent of the first session setup process;

receiving a media stream transmitted from the second SIP-like terminal to the gateway;

processing the media stream;

providing an intra-coded frame; and

thereafter, transmitting the intra-coded frame and the processed media stream from the gateway to the first SIP-like terminal.

17. The method of claim 16 further comprising:

receiving a second media stream transmitted from the first SIP-like terminal to the gateway; and

transmitting the second media stream from the gateway to the second SIP-like terminal.

18. The method of claim 16 wherein a number of video capabilities in the first capability response message is less than a number of video capabilities in the first capability message.

19. The method of claim 18 wherein the number of video capabilities in the first capability response message is one.

20. The method of claim 16 wherein a number of audio capabilities in the first capability response message is less than a number of audio capabilities in the first capability message.

21. The method of claim 20 wherein the number of audio capabilities in the first capability response message is one.

22. A method of establishing a reduced setup time session between a first SIP-like terminal and a second SIP-like terminal, the session being conducted through a gateway, the method comprising:

performing a first session setup process between the first terminal and the gateway;

performing a second session setup process between the second terminal and the gateway, the second session setup process being performed independent of the first session setup process wherein performing the second session setup process comprises:

transmitting a second INVITE message from the gateway to the second SIP-like terminal;

receiving a second capabilities response message transmitted from the second SIP-like terminal to the gateway;

processing the second capabilities response message; and

transmitting an acknowledgement message from the gateway to the second SIP-like terminal;

receiving a media stream transmitted from the second SIP-like terminal to the gateway;

processing the media stream;

providing an intra-coded frame; and

thereafter, transmitting the intra-coded frame and the processed media stream from the gateway to the first SIP-like terminal.

23. The method of claim 22 wherein the second INVITE message comprises an empty INVITE message.

24. The method of claim 22 wherein the acknowledgment message includes an SDP-like message.

25. The method of claim 24 wherein a number of video capabilities in the SDP-like message is less than a number of video capabilities in the second capability response message.

26. The method of claim 25 wherein the number of video capabilities in the SDP-like message is one.

27. The method of claim 24 wherein a number of audio capabilities in the SDP-like message is less than a number of audio capabilities in the second capability response message.

28. The method of claim 27 wherein the number of audio capabilities in the SDP-like message is one.

29. The method of claim 16 wherein processing the media stream comprises identifying a temporal feature in the media stream that enables a decoder to establish a decoder refresh point.

30. The method of claim 29 wherein the temporal feature comprises an intra-coded frame.

31. The method of claim 29 further comprising generating a VideoFastUpdate-like message and transmitting the VideoFastUpdate-like message from the gateway to the second terminal.

32. The method of claim 16 wherein processing the media stream further comprises generating an intra-coded frame.

33. The method of claim 32 wherein generating the intra-coded frame comprises converting an inter-coded frame into an intra-coded frame.