The osmo-mgw log at the time:
Aug 03 21:05:16 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/1@mgw CRCX: creating new connection ...
Aug 03 21:05:16 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, nt:IN"
Aug 03 21:05:16 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/1@mgw CI:C5FA0139 Failed to send dummy RTP packet.
Aug 03 21:05:16 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/1@mgw CI:C5FA0139 CRCX: connection successfully created
Aug 03 21:05:18 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/2@mgw CRCX: creating new connection ...
Aug 03 21:05:18 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, nt:IN"
Aug 03 21:05:18 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/2@mgw CI:5FEF0014 Failed to send dummy RTP packet.
Aug 03 21:05:18 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/2@mgw CI:5FEF0014 CRCX: connection successfully created
Aug 03 21:05:37 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1234 endpoint:rtpbridge/2@mgw DLCX: deleting connection ...
Aug 03 21:05:37 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1345 endpoint:rtpbridge/2@mgw DLCX: connection successfully deleted
Aug 03 21:05:37 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1234 endpoint:rtpbridge/1@mgw DLCX: deleting connection ...
Aug 03 21:05:37 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1345 endpoint:rtpbridge/1@mgw DLCX: connection successfully deleted
Aug 03 21:05:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/1@mgw CRCX: creating new connection ...
Aug 03 21:05:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, nt:IN"
Aug 03 21:05:54 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/1@mgw CI:F935122B Failed to send dummy RTP packet.
Aug 03 21:05:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/1@mgw CI:F935122B CRCX: connection successfully created
Aug 03 21:05:55 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/1@mgw MDCX: modifying existing connection ...
Aug 03 21:05:55 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/1@mgw CI:F935122B Got media info via SDP: port:6000, addr:192.168.11.179, duration:20, payload-types:3=GSM
Aug 03 21:05:55 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/1@mgw CI:F935122B MDCX: connection successfully modified
Aug 03 21:05:55 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/1@mgw CRCX: creating new connection ...
Aug 03 21:05:55 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, a:GSM, nt:IN"
Aug 03 21:05:55 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/1@mgw CI:3D08AA4D Failed to send dummy RTP packet.
Aug 03 21:05:55 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/1@mgw CI:3D08AA4D CRCX: connection successfully created
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/2@mgw CRCX: creating new connection ...
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, nt:IN"
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/2@mgw CI:D8B6D7ED Failed to send dummy RTP packet.
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/2@mgw CI:D8B6D7ED CRCX: connection successfully created
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/2@mgw MDCX: modifying existing connection ...
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/2@mgw CI:D8B6D7ED Got media info via SDP: port:6002, addr:192.168.11.179, duration:20, payload-types:3=GSM
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/2@mgw CI:D8B6D7ED MDCX: connection successfully modified
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/2@mgw CRCX: creating new connection ...
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, a:GSM, nt:IN"
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/2@mgw CI:73ECFD0A Failed to send dummy RTP packet.
Aug 03 21:05:57 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/2@mgw CI:73ECFD0A CRCX: connection successfully created
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/2@mgw MDCX: modifying existing connection ...
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/2@mgw CI:73ECFD0A Got media info via SDP: port:4910, addr:192.168.11.4, duration:20, payload-types:3=GSM
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/2@mgw CI:73ECFD0A MDCX: connection successfully modified
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/1@mgw MDCX: modifying existing connection ...
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/1@mgw CI:3D08AA4D Got media info via SDP: port:4914, addr:192.168.11.4, duration:20, payload-types:3=GSM
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/1@mgw CI:3D08AA4D MDCX: connection successfully modified
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:1100 (rtpbridge/1@mgw I:3D08AA4D) RTP packet too short (1 < 12)
Aug 03 21:06:00 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:1100 (rtpbridge/2@mgw I:73ECFD0A) RTP packet too short (1 < 12)
Aug 03 21:07:24 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1234 endpoint:rtpbridge/1@mgw DLCX: deleting connection ...
Aug 03 21:07:24 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1345 endpoint:rtpbridge/1@mgw DLCX: connection successfully deleted
Aug 03 21:07:24 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1234 endpoint:rtpbridge/1@mgw DLCX: deleting connection ...
Aug 03 21:07:24 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1345 endpoint:rtpbridge/1@mgw DLCX: connection successfully deleted
Aug 03 21:07:27 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1234 endpoint:rtpbridge/2@mgw DLCX: deleting connection ...
Aug 03 21:07:27 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1345 endpoint:rtpbridge/2@mgw DLCX: connection successfully deleted
Aug 03 21:07:27 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1234 endpoint:rtpbridge/2@mgw DLCX: deleting connection ...
Aug 03 21:07:27 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1345 endpoint:rtpbridge/2@mgw DLCX: connection successfully deleted
Aug 03 21:08:53 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/1@mgw CRCX: creating new connection ...
Aug 03 21:08:53 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, nt:IN"
Aug 03 21:08:53 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/1@mgw CI:14980A56 Failed to send dummy RTP packet.
Aug 03 21:08:53 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/1@mgw CI:14980A56 CRCX: connection successfully created
Aug 03 21:08:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/1@mgw MDCX: modifying existing connection ...
Aug 03 21:08:54 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/1@mgw CI:14980A56 Got media info via SDP: port:6004, addr:192.168.11.179, duration:20, payload-types:3=GSM
Aug 03 21:08:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/1@mgw CI:14980A56 MDCX: connection successfully modified
Aug 03 21:08:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/1@mgw CRCX: creating new connection ...
Aug 03 21:08:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, a:GSM, nt:IN"
Aug 03 21:08:54 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/1@mgw CI:B935AEC5 Failed to send dummy RTP packet.
Aug 03 21:08:54 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/1@mgw CI:B935AEC5 CRCX: connection successfully created
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/2@mgw CRCX: creating new connection ...
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, nt:IN"
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/2@mgw CI:9CF30986 Failed to send dummy RTP packet.
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/2@mgw CI:9CF30986 CRCX: connection successfully created
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/2@mgw MDCX: modifying existing connection ...
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/2@mgw CI:9CF30986 Got media info via SDP: port:6006, addr:192.168.11.179, duration:20, payload-types:3=GSM
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/2@mgw CI:9CF30986 MDCX: connection successfully modified
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:749 endpoint:rtpbridge/2@mgw CRCX: creating new connection ...
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:571 LCO: unhandled option: 'n'/110 in "p:20, a:GSM, nt:IN"
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:206 endpoint:rtpbridge/2@mgw CI:6324977B Failed to send dummy RTP packet.
Aug 03 21:08:56 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:983 endpoint:rtpbridge/2@mgw CI:6324977B CRCX: connection successfully created
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/2@mgw MDCX: modifying existing connection ...
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/2@mgw CI:6324977B Got media info via SDP: port:4918, addr:192.168.11.4, duration:20, payload-types:3=GSM
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/2@mgw CI:6324977B MDCX: connection successfully modified
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1009 endpoint:rtpbridge/1@mgw MDCX: modifying existing connection ...
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0011> mgcp_sdp.c:394 endpoint:rtpbridge/1@mgw CI:B935AEC5 Got media info via SDP: port:4922, addr:192.168.11.4, duration:20, payload-types:3=GSM
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0011> mgcp_protocol.c:1211 endpoint:rtpbridge/1@mgw CI:B935AEC5 MDCX: connection successfully modified
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:1100 (rtpbridge/1@mgw I:B935AEC5) RTP packet too short (1 < 12)
Aug 03 21:08:58 apu-left osmo-mgw[6846]: <0000> mgcp_network.c:1100 (rtpbridge/2@mgw I:6324977B) RTP packet too short (1 < 12)