Cellular Network Infrastructure » OsmoMGW

With #6448 completed, Osmocom BSS now supports Themyscira RTP extensions (at least for FR & EFR; HR is blocked by #6036) with native OsmoBTS: the CN requests the use of extended RTP payload formats via BSSMAP, OsmoBSC passes that request to OsmoBTS, and the RTP stream from TCH UL becomes the enhanced form. Now let's implement the same capability with E1 BTS, where the responsibility for turning TCH UL (transmitted by the BTS as TRAU-UL frames) into RTP falls on OsmoMGW.

To achieve this feat, we will need an extension to the MGCP dialect of OsmoMGW whereby OsmoBSC will be able to command E1-interfacing OsmoMGW to turn on ThemWi RTP extensions. (The necessary support in the trau2rtp layer in libosmotrau has already been implemented and merged, but the control mechanism is the lacking part.) MGCP is an area which I haven't had to touch yet, hence I am not certain how to proceed here.