scope:

This Recommendation describes packages for the H.248.1 gateway control protocol related to interworking of H.323 and H.324 terminals, as follows:

− Package "h324" for termination of H.324 bitstream on MGs.

− Package "h245" for termination of H.245 messages on MGs.

− Package "h323bc" for H.245 parameters specific to H.323.

− Package "h245com" for providing properties that allow the MGC to indicate to the MG that the MGC has sent or received an H.245 command.

− Package "h245ind" for providing properties that allow the MGC to indicate to the MG that the MGC has sent or received an H.245 indication.

With the terminations implementing "h324", "h245com" and "h245ind" packages, the decomposed gateway may support H.324 communication with the H.245 control function in the MGC. In the H.324 and H.323 interworking scenario with this decomposed gateway, H.245 control messages are terminated in the MGC (a backhaul is used between the MG and the MGC to transport H.245 messages between the MG and the MGC, on the H.324 side). The terminations for media on both H.324 and H.323 sides are managed by the MGC.

With the terminations implementing "h324" and "h245" packages, the decomposed gateway may support H.324 communication with H.245 control in the MG. In the H.324 and H.323 interworkingscenario with this decomposed gateway, H.245 control messages from the H.324 side and the H.323 side are terminated in the "h245" termination and in the "h323bc" termination respectively, and are processed in the MG. The MG manages the logical channels for media.

Annex A describes extended H.324, H.245 command, H.245 indication and H.245 transport packages for interworking with H.324 terminals having different H.324 capabilities, when the interworking function is handled by the MGC.