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The sipX authorization proxy is responsible for enforcing the permissions that govern which users and phones can call PSTN numbers. In order for that enforcement to be effective, the gateway must not accept calls that do not come from the proxy (also see Securing Calls to the PSTN). To configure this restriction, there are two settings: the Tel to IP to Tel Routing Table, and the IP Security parameter.
Select the Tel to IP to Tel Routing Table and add a row for each proxy in your configuration (you will only have one unless you are running a High Availability system with redundant proxy servers). Each row has just <tt>*</tt> for the number prefix values, the IP address of a proxy, and the default tel profile number:
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