No audio when calling mobile phones

[drodner]

Hi,

We have an Allworx 6x. Most of our phones are in our local office and everything works fine. I have one remote phone (the phones are Allworx 9212) that works fine except for one nagging problem. When calling a mobile phone, there is no audio. I see the call connect and the timer on the phone's screen starts counting, but the recipient cannot hear me and I cannot hear him. If the mobile phone calls in, however, the audio is fine. So it's just a remote phone dialing out to mobile phones that has this problem. (Calling land lines does not have an audio problem).

Has anyone else experienced this or know how to fix it?

Thanks!

[Allworx6xCT]

I'm not an installer, but it sounds to me like it could be a port forwarding issue. Check the firewall settings.

[drodner]

Hi Chris,

I thought about that and didn't find anything being blocked in the firewall. I will double-check that, though. Also, wouldn't the port(s) for audio be the same for incoming calls as it is for outgoing calls? Or at least wouldn't the ports for mobile calls be the same regardless of incoming/outgoing?

Thanks,
Darren

[jeff]

Darren -

In the Allworx web portal Home > Servers >VoIP Server, are your forcing remote phone audio through server? If that is enabled, depending in how the firewall is configured on the local office network and remote phone network (and modem if a cable ISP), make sure there is no double NAT going on. Have found with a few of our remote phones, if they have a router at home with SIP Alg enabled or NAT on both firewall and ISP modem, we have the same issue. You don't really want any other NAT happening because the 6x is doing the NAT traversal.

If it is disabled, then on the remote phone network, you definitely need to port forward all needed ports because the server is not doing any NAT traversing.

In short, before I checked the 6x settings, I would open UDP ports 15000-15511 and 16384-37627 on the local and remote office firewalls, disable any SIP Alg's that may be running on the remote office network. If that doesn't help, run the Call Control Backplane Messages and SIP messages advanced diagnostic logging under Home > Maintenance > Tools for one call from the remote phone to the mobile phone and you should be able to find the problem fairly quickly.

Let us know how it turns out.
Thx,
Jeff

[drodner]

Hi Jeff,

Turning off the force remote audio through server setting seems to have fixed it. Since turning that off I've called a few mobile phone numbers and all have been successful.

Thanks for the assistance!

-- Darren