Enable NAT to receive calls
If you have an IP phone that’s able to make calls but unable to receive calls, it can usually be resolved by enabling the NAT setting on the device.
In most cases, issues with receiving calls are caused by your organization’s network router or firewall. By enabling Network Address Translation (NAT) on your phone, Telzio calls can find their way through the router and to your phone.
Most IP phones have a setting to turn on NAT. Start by enabling the NAT setting on your IP phone and see if that resolves the issue.
Your IP phone may need to know the IP of your network in order to enable NAT. You can find your IP by searching for “my IP” on Google. Type this IP address into the field provided in the phone settings.
If your phone has the ability to use a STUN server, you can use the following STUN server address: