Inbound call to IVR doesn’t always have audio

Hello,

I have managed to configure FreePBX with a SIP Trunk to VoIPRaider. The Inbound Rules redirect to my IVR and when the correct extension was chosen by the caller, my softphone app rings, I can pick it up and hear the other side correctly. They can also hear me.

However, sometimes the IVR picks up the phone, but the caller doesn’t hear any sound. Then calling for a second time, everything works correctly. I also have had the same issue with software of the competition.

Yes, the system is behind a NAT, but when I used a public IP for everything, it didn’t make any difference. Any idea’s where the problem could be and how to potentially solve it?

Audio issues are almost always related to improperly configured NAT and port forwarding. Make sure you have your IP settings set correctly in Asterisk SIP Settings and have your RTP range port forwarded in your NAT device back to the internal IP for the phone system.

Thank you. But I also have the same issue when I use a public IP, outside the NAT.