The settings that we show here applie to version X-Lite release 1103m, see xten. If you set the phone up the right way you can make phone calls from public Internet and various kinds of NAT networks (single tier full-cone or symmetrical, two-tier networks). We show here the configuration for a hypothetical provider test.co.uk which is providing the account 700.

X-Lite is trying to allocate a public IP address in most cases. While this is working in many cases, in the other cases it does not work properly. Symptoms are that you can make outbound calls, but are not able to receive inbound calls etc. We recommend turning the public IP allocation algorithm off. The internal session border controller of the pbxnsip takes care about the NAT problems and makes sure that it will work even behind symmetrical NAT.

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The following screen shots show what configuration was working in our installation. The first screen shot is from the network menu.



The next screen shot shows the settings for the default line. Please notice that we always use the outbound proxy.



X-Tunnels is a proprietary protocol from X-Lite by which they try to solve the cases where the STUN NAT detection does not work. Because we use the session border controller, this feature is not helpful and we turn it off.



The same applies for the STUN settings. We took the STUN server completely out, because out X-Lite was still trying to allocate a public IP address, although we turned the public IP address allocation off.



On the next page you should not need to change anything, just make sure that you did not screw anything up.



Make sure that X-lite is using out of band codec (RFC2833). Inband is not a reliable way of transporting DTMF digits.