We are currently setting up our new VoIP phone system, using SIPStation SIP trunks, and a Sangoma PBXact40 PBX. I have SIP traffic working fine (can call inbound/outbound) without issues, but no matter how I configure our Balance 30 Pro LTE router, the RTP traffic fails to go through leaving us with no audio either way. I believe I have set the appropriate inbound firewall rules, as well as the necessary port-forwarding rules:
When I do capture on the PBX, I can here the audio in the outbound RTP stream, however, the person at the other end never hears it, nor do I see/hear the inbound RPT stream.
We have dual WANs setup, with a cable and dsl broadband connection.
The SIPStation support person believes that the router is somehow blocking the RTP traffic. This is so frustrating as there is nothing to indicate what the problem might be.
Any assistance would be greatly appreciated. Thanks.