Gateway loses registration after network problems


Hi Everybody,

I have a GXW4108 gateway connected to a 3cx PBX, but in different networks. (The PBX is running in my own cloud and the gateway is running in the customer office)
If the gateway for some reason loses connection with the PBX (such as internet problems) it will no longer be registered unless it is restarted.
I don’t know if that is an appropriate scenario.
I don’t know how to check if the gateway asks for registration again once the network connection is restored and the registration time expires.
Any ideas?

Thanks in advance



Are you port forwarding? Is the gateway located behind a static or dynamic public IP?


Hi Ipneblett, thanks for the reply!

The only port that’s being forwarded is 5060.
The gateway is located behind a static public IP


Does the gateway have a NAT IP set with the static public IP of the remote site (where it sits)?


Do you mean a configuration on the edge router?
No, there is not.
But the question is why every time I restart the gateway, it register

Thanks in advance


What kind of network problems and where do you see the loss of registration, at the GXW or the device to which it is connected and sending the calls?

I assume you see the loss in 3CX, but what does it show at the gateway.

When a device registers it requests and is given an expiry time. The expiry is the amount of time that the device has been given such that if no calls or other messaging is needed, the GXW will not need to contact 3CX again until the expiry is reached whereupon the GXW will register once again.

If the Internet goes out, the GXW may not know this and will continue to show being registered on its end while 3CX does not.

You need to check and see.

Additionally, it sounds like there is a possibility that you are not handling the NAT correctly. If you are not forwarding to the GWX, then are SIP Options keep alives enabled? Is STUN set and enabled or a NAT IP (if the remote has a static public IP) set. If not, then how does 3CX know where to find the GXW. The GXW knows where to contact 3CX as you provisioned a SIP server into it, but what about the return side? How do you ensure that the messaging from 3CX is going back to the public IP where the GXW is located and then thru the firewall to the GXW itself?


I’m going to check and then I’ll let you know.



I think this is a better description of the problem…

We notice the problem when the internet connection on the gateway side drops.
We simulate the problem by disconnecting the network cable from the gateway. When we connect it again, it cannot make calls until we restart it.
It is registered in the PBX, but the gateway cannot make calls. After restarting the gateway it works again


Daniel, remove registration and make the GXW4108 be IP based use the external IP as the destination and all should be fine - just has to be routable IP addy and obviously at the 3cx end make it IP based and not reg based. No more registration issues after that.


I enabled the STUN configuration on the gateway, and everything seems to be working fine now.
Thanks to you all !!