No audio on externally forwarded calls


Freepbx:, asterisk 13.29, with pjsip and behind NAT
Sip and RTP ports open/forwarded in the firewall to the PBX

Direct Calls, inbound and outbound, are working file.

but when inbound call is forwarded (*72) to an external number: phone is ringing but no audio

help would be appreciated.

This is usually a symptom of not forwarding the full RTP range, so double check that router rule, it’s not working for you. You can bandaid by answering the channel on the inbound route, or by adding progressinband if using chan_sip.

  • Double checked the RTP port forwarding : seems OK

  • I’m using pjsip

  • “Force answer” set to yes on the inbound route solved the issue.

Thanks for your help!

The answer has the effect of sending RTP out from the PBX before the call gets forwarded. I still maintain that your router forwarding for RTP is not working.

Indeed, you are right.

A part of the port range was in overlapping with another rule and routed to the wrong server.

Thanks for you quick help.

1 Like

This topic was automatically closed 7 days after the last reply. New replies are no longer allowed.