3cx Stun problem

[wyslink]

ip phone send binding request to 3cx stun server, but no response with a mobile router, anyone knows the reason?

 

[NickD_3CX]

Maybe the ISP or your router is blocking the STUN requests?
Wouldn't be the first time I have heard of something like this.

If your router has packet capturing capabilities, you could run a capture on these and check if these packets re leaving the router.

Also, usually IP Phones send the STUN requests to the same IP of the 3CX PBX, not directly to the STUN servers.

 

[ChrisC_3CX]

@wyslink
As NickD_3CX mentioned, the STUN requests may not be reaching the 3CX PBX at all, what you could do in order to confirm this is also run a packet capture on the 3CX PBX while also running a packet capture on the IP Phone, then check if you can see the STUN requests in both the 3CX PBX packet capture and the IP Phone packet capture.

To perform a packet capture on the 3CX PBX, simply access the Management Console, navigate to Dashboard >> Activity Log >> Select the main interface in the drop-down list and then click on "Capture". When you Stop the packet capture, you'll be provided with two links, the first one is to download the .pcap file directly. Do remember to run the packet capture on both the IP Phone and PBX at the same time so that you can compare them.

 

[Cytranic]

Is this any sort of ISP thaty offers VOIP service? AT&T for example block ports used for VOIP on their networks if you are on a plan that offers VOIP.