Remote extension not sending sound...

[sms_newb]

Ive set up a 3CX PBX server in our office that went together fairly easily, ive auto provisioned 3 Grandstream GXP 1450 phones and sent one of them to a remote worker, with the intention that we can communicate with each other via the voip phones. The extensions worked fine communicating with each other within the LAN, but when the hardphone is external I can not hear any sound coming through.

So the external phone can hear me, but I (in PBX LAN) can not hear the external extension.

What could be causing this? Is the router at the remote end blocking outgoing sound? Or the router at this end blocking incoming sound?

15:25:00.204 [CM503008]: Call(77): Call is terminated
15:24:53.080 [CM503007]: Call(77): Device joined: sip:[email protected]:64092;user=phone
15:24:53.077 [CM503007]: Call(77): Device joined: sip:[email protected]:5060;user=phone
15:24:50.468 [CM505001]: Ext.14: Device info: Device Identified: [Man: Grandstream;Mod: GXP Series;Rev: General] Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [Grandstream GXP1450 1.0.1.66] PBX contact: [sip:[email protected]:5060]
15:24:50.467 [CM503002]: Call(77): Alerting sip:[email protected]:64092;user=phone
15:24:50.232 [CM503025]: Call(77): Calling Ext:Ext.14@[Dev:sip:[email protected]:64092;user=phone]
15:24:49.831 [CM503004]: Call(77): Route 1: Ext:Ext.14@[Dev:sip:[email protected]:64092;user=phone]
15:24:49.829 [CM503010]: Making route(s) to <sip:[email protected];user=phone>
15:24:49.825 [CM505001]: Ext.13: Device info: Device Identified: [Man: Grandstream;Mod: GXP Series;Rev: General] Capabilities:[reinvite, replaces, able-no-sdp, recvonly] UserAgent: [Grandstream GXP1450 1.0.1.66] PBX contact: [sip:[email protected]:5060]
15:24:49.821 [CM503001]: Call(77): Incoming call from Ext.13 to <sip:[email protected];user=phone>

 

[sms_newb]

I will DMZ the IP of the phone if I can get into the router config settings, which im struggling with. Safari wont take me to the IP address when I put it in the address bar.

 

[leejor]

I will DMZ the IP of the phone if I can get into the router config settings, which im struggling with. Safari wont take me to the IP address when I put it in the address bar.

Unless you VPN into your remote router, you can't use the private IP of the remote device. You have to use the public IP plus the port number that you gave the device (5060?), however, for this to work you need to have that port forwarded, in the router to the IP of the device.

 

[nbailey]

If attempting a remote extension without using the tunnel (sip proxy or tunnel for softphone) 9000-9049 UDP need to be forwarded correctly and 5060 as mention before, be sure STUN is setup properly and rport and keep alives setup (15-20 sec.)
Static port mappings are necessary also. maybe I missed some comments and I hope not, it wouldn't matter MAC or PC, maybe I am missing something but really 5060 forwarded correctly and 9000-9049 forwarded should work. It depends on the router and proper configuration. And STUN correctly setup as well as rport enabled and keep alives. Direct remote extensions can be a pain and there is more router config and port mapping then anything stopping you from your goal. good luck!!

 

[SRV369]

Hello,

It's definitely the Grandstream phone. I had the very same problem and was able to solve it with the following:

Go to the phone's web interface:

There should be an option called "use symmetric RTP", make sure it is selected and also NAT (stun) is also set to yes.