Our ITSP insists we use one address for signalling and they’ve given us another to use for media. Is there somewhere to set this up in Freesbc or do we leave this to be is negotiated in call setup?
On the internal trunk to PBX I can see and playback two-way audio in wireshark. So this seems to be fine. On outside I only see audio one way and that is ITSP → FreeSBC in trace. No RTP FreeSBC → ITSP relaying what is taking place on the inside trunk. Am I missing something?
On softphone connected to PBX I can hear incoming audio but nothing going back out (testing with mobile). From the above traces it seems inside trunk is ok as I can see two way audio in wireshark and play it back but outside there is a relaying problem as I can only see RTP coming inbound from ITSP and nothing going back out replicating what I see inside.
The media address is announced in the SDP as below (have ??'d out addresses) media is 194, signalling on 193 here
You can use different IP addresses for signaling and media. First you need to set new IP interface for signaling and media and in the NAP settings Port Range section select the RTP range for media IP. In this case signaling will go from one IP address and media will go from another IP address.
SBC is not caring if ITSP used different IP addresses for media and signaling. SBC will check connection information in the received SDP and start to send the RTP to that IP addresses even SIP Signaling IP is different.