Can make calls out not in

[venkman]

Hi,

I am setting up the 3CX as a proof of concept to decide whether our business can move over from our current system. So at the moment I am using the free 2 channel and don't have any support.

I've set up a SIP trunk, and I am able to make calls:

- From softphone to softphone
- From softphone to an external telephone number (via the SIP trunk)

However, when I try and call the number, it just rings until it gets disconnected. There are no logs in the PBX, so it looks like it's not even hitting the 3CX system. I've contacted the SIP provider and they have advised that they can see that these inbound calls are timing out, due to 'Recovery On Timer Expiry', and nine times out of ten that is associated with NAT related issues, and that it is likely that were are not listening to the address/port that we are advertising to the provider to use.

Unfortunately, I'm not really sure what they mean by this; I've run the firewall checker and it's passing with no issues, so I'm hoping someone in this forum can help me out?

Thanks

 

[superior1]

I would advise to run Wireshark (wireshark.org)on the computer running 3CX. Start a capture of all traffic. In the filter section type ip.addr == x.x.x.x then apply. X represents the SIP trunk providers IP address.

Verify if any request are coming from that IP. That would show more than the Activity Log by 3CX.

If you have a laptop handy and a old fashion hub (not a smarthub), you can run wireshark in between all connections and really see if you are requests from the provider.

If firewall checker shows all Passes, then I would suspect routing from the provider and or port forwarding of port 5060 not working properly.

 

[leejor]

So in the 3CX Server logs, there is no indication of an incoming call?

When you spoke to your provider, did you ask what IP (and port) they showed you being registered with? If that didn't match with what you think it should be, then it may be STUN related. the fact that you can place a call would suggest otherwise, but worth asking anyway. If they do see the correct IP/port, then I would suspect the router (setting?), or firewall, if you use one. What model router are you using? Does the 3CX PC/server have more than one NIC?

 

[venkman]

[quote="leejor" If they do see the correct IP/port, then I would suspect the router (setting?), or firewall, if you use one. What model router are you using? [/quote] Thanks for the reply, turns out it was a firewall issue. It was a SIP-ALG issue. Can now make calls in.

Thanks all for the help!