Translate PT before sending RTP packets (different PT numbers, but same codec on two connections)
When dynamic payload types are used and the call-agent configures two connections with the same codec, but different payload type numbers then osmo-mgw must ensure that the RTP packets are sent with the correct payload type number. This means on the ingress connection the MGW must lookup the codec by the payload type number. On the egress connection the MGW must use the previously looked up codec to determine the matching payload type number that is configured for that codec on the egress connection.
We need: Payload-type number re-writing in osmo-mgw and a TTCN3 testcase that verifies this behavior.