This should really be using the FSM in libosmocore/laforge/iu_up: take the best
of both sides and integate in the libosmocore FSM implementation, then use it
here.
- in libosmocore, the FSM definition is nicer.
- here, we have correct header checksums.
Introduce using msgb to receive, pass and send RTP packets.
Add/strip IuUP from RTP data (for which msgb is particularly useful).
The payload type on an IuUP conn is maintained as negotiated in the IuUP
Initialization. For the pure RTP side, an SDP "AMR" ptmap attribute is looked
up, so that payload type numbers are translated between IuUP <-> RTP.
Change-Id: Ibc70e0aa00476926dd1f4ea8139c34f31f9cdfa3
fbe05d8b1f