No audio on forwarded call


2 freePBX distro’s at 2 offices connected via VPN. I setup a ring group that rings local extensions first. If not answered it goes to a second ring group that simply dials the number of the other office. This works fine but there is no audio, can’t hear or be heard. The connection is established and remains until one party hangs up but there is never any sound.

I tried to have the second ring group dial the extensions at the other office directly but that was too messy so dialing the office number is much cleaner. If I can just get over this last hurdle I will be finished setting this up. Please help!

I called Nextiva support (my sip provider) and they suggested that I set an access rule in my router allowing their signaling IP address full access as well as the WAN address of both offices. I run an IPCop router and I don’t see a way to give an external IP address “full access”.

Any suggestions?


If you have Asterisk SIP settings set to “Static IP” for life behind a firewall, be certain that both of them have all internal IP networks in the “local networks” field and add more fields if necessary.

For example if site 1 is and site 2 is, both FreePBX Asterisk SIP settings “local network entries” fields need to have both subnet values.

For me, since I cannot ever imagine needing NAT help for an RFC 1918 private address, I put all 3 in the local network entries fields just to avoid any problems in the future…

I cant speak for IPCOP, but some VPN’s have a keep-alive feature that may help as well.

Additionally, if necessary, the trunks between the two PBX’s have could have qualify=yes and qualifyfreq=(some low number of seconds) in order to simulate a keep alive.

Another thing to try is IAX trunks between FreePBX servers and use SIP only to the external providers and phones.

All of this should prevent PBX 1 from sending audio to the external IP of PBX2 since the PBX2 server is available via LAN over VPN and vice versa.

Good luck!

Personsz, I haven’t been working with this stuff long and I’m far from an expert. My frustration with using this forum has been caused by people who answer me as if I’m homeless person begging for change. Your answer is the best, well written and thought out answer I’ve received yet. Thank you and give yourself a gold star :wink:

Petersonz, not Personz - Sorry

I forgot yet another thing you might do… Off topic…

Ask the SIP provider to send inbound calls in an IP hunt group so that both PBX’s. This way you have inbound and outbound redundancy should one of your internet connections go down.

For example, Broadvox charges just $10 per month for this service.

Other providers dont charge for this at all.