Summary

Recommendation ITU-T H.248.78 defines a package that allows bearer-level application protocol (such as real-time streaming protocol (RTSP) or message session relay protocol (MSRP)) messages received by a media gateway (MG) to be communicated to a media gateway controller (MGC). This allows the MGC to perform application-level gateway functionality such as network address translation on the messages and then forward the messages to the MG for sending to the destination.

The 03/2013 revision incorporates an update to correctly refer to the "Message Session Relay Protocol".

The 04/2015 revision adds a further ITU-T H.248 package for support of:

a)          MG located application-level gateway functionality; and

b)          MG message backhauling functionality.

It also updates the title from "bearer-level application level gateway" to "bearer-level message backhauling and application level gateway".

This 11/2015 revision adds Annex A that describes Extensible Messaging and Presence Protocol (XMPP) to MSRP interworking utilising mechanisms defined in this Recommendation.