No incoming audio on Raspberry Pi PBX

1

I have my calls being call forwarded to my cell phone from my incoming DID’s that are processed through my raspberry pi pbx (which is connected to my router). I kept getting phone calls since I set it up but when I picked up the call on my cell phone there was never a voice on the other end so I thought they were prank calls. Direct calls to my cell work fine so I finally tested calling my DIDs from another phone and it turns out the audio is not being transmitted!

Does anyone know what settings I might have wrong?

2

I believe you just faced an old well-known problem.
For test you can have the call first answered by IVR then forwarded to cell. This will create an outgoing UDP stream from the PBX which will open a pinhole on your NAT.
For a complete fix you need to configure a port forwarding on your router for the whole RTP range used by PBX.

3

Thanks, I would like a complete fix as I just want to answer from my cell phone and not have the IVR as an intermediary

I found that the default RTP port range in Settings|Asterisk SIP Settings is 10,000-20,000. So, in my router settings I went to the Port Range Forwarding section and configured that range for the choice ‘Both’, ie TCP & UDP, to the network address of my Raspberry Pi, which is 192.168.1.105. Is this correct and then clicked ‘Enable’? Is this correct?

4

You can probably limit the RTP range first (I have 100 ports myself) then configure the port forwarding for the same range (UDP only!) and IP address of PBX.

5

Thanks. I got it working with the 10,000-10,100 set on both the PBX and on the router. I assume both have to be exactly the same? Why is fewer ports better? Also, why is it UDP only?

6

You want ‘progressinband’ enabled in SIP settings:

7

Thanks. With it working ok without adding the progressinband=yes line do I really need to add it?