Cellular Network Infrastructure » Radio Access Network » OsmoBSC

if you look at the pcap in https://osmocom.org/attachments/7192 from #6258
you'll see that the Channel Mode Modify in packet 5368 changes the codec from GSM-FR to AMR,
but then the AMR payload in RTP continues to indicate PT=3 instead of the expected PT=112.

This is because osmo-bsc still fails to:

• tell the MGW about the changed codec and payload type number via MGCP MDCX
• tell the BTS to emit the changed payload type number via ipacc.MDCX

This should happen in lchan_fsm.c in lchan_fsm_wait_rsl_chan_mode_modify_ack() on rx of LCHAN_EV_RSL_CHAN_MODE_MODIFY_ACK.
The lchan_fsm.c should tell the lchan_rtp_fsm.c to change the payload type number and codec.
When lchan_rtp_fsm.c is done with both MDCX, it should signal LCHAN_EV_RTP_READY back to lchan_fsm.