Half sided calls

Hello! I can confirm a compatiblity issue with LibORTP >= 0.24.0. Here are some of my findings: In /osmo-bts/src/common/rsl.c in rsl_rx_ipac_XXcx there is a call to libosmo-abis function: osmo_rtp_socket_bind(lchan->abis_ip.rtp_socket, ipstr, -1). I assume, that last argument "-1" means that the random udp port should be selected for socket. in /libosmo-abis/src/trau/osmo-rtp.c in a function int osmo_rtp_socket_bind(struct osmo_rtp_socket *rs, const char *ip, int port) there is a call to LibORTP rtp_session_set_local_addr(rs->sess, ip, port, port+1). So as result this function calls rtp_session_set_local_addr with last arguments being equal to "-1" and "0". The LibORTP function int rtp_session_set_local_addr (RtpSession * session, const char * addr, int rtp_port, int rtcp_port) has a folollowing description: /** *rtp_session_set_local_addr: *@session: a rtp session freshly created. *@addr: a local IP address in the xxx.xxx.xxx.xxx form. *@rtp_port: a local port or -1 to let oRTP choose the port randomly *@rtcp_port: a local port or -1 to let oRTP choose the port randomly * ... **/ So this results in calling osmo_rtp_socket_bind(...,-1) -> rtp_session_set_local_addr(...,-1,0) what tries to bind rtp to random udp port and rtcp to 0th udp port, but not to random port. I guess that rtcp socket is never created regardless of LibORTP version. (there are periodic osmo-ortp(): network_error osmo-bts log messages due to ICMP port unreachable messages received, besides those mentioned in https://osmocom.org/issues/1662). So I suppose the correct code should check port value and either calling rtp_session_set_local_addr(rs->sess, ip, port, port+1) if port >0 or else calling rtp_session_set_local_addr(rs->sess, ip, port, port) ? Also, after inspecting sources of LibORTP it seems that the implementation of rtp_session_set_local_addr has changed for LibORTP >= 0.24.0. As I understand the functionality of selecting a random UDP port is broken. What results is one way audio. Regards, Pavel.