Hello;
There is a rtptimeout problem. it is setted 121 second and even if there is rtp flow both side and can hear both side , it disconnect both side for lack rtp.
I think it is bug.
it uses chan_rtp and chan_sip
[Nov 1 17:28:55] NOTICE[23377]: chan_sip.c:29402 check_rtp_timeout: Disconnecting call ‘SIP/kamailio4-00001067’ for lack of RTP activity in 122 seconds
[Nov 1 17:28:55] NOTICE[23377]: chan_sip.c:29402 check_rtp_timeout: Disconnecting call ‘SIP/kamailio4-00001068’ for lack of RTP activity in 122 seconds