freeswitch/conf/vanilla/autoload_configs/xml_rpc.conf.xml

<configuration name="xml_rpc.conf" description="XML RPC">
  <settings>
    <!-- The port where you want to run the http service (default 8080) -->
    <param name="http-port" value="8080"/>
    <!-- if all 3 of the following params exist all http traffic will require auth -->
    <param name="auth-realm" value="freeswitch"/>
    <param name="auth-user" value="freeswitch"/>
    <param name="auth-pass" value="works"/>
  </settings>
</configuration>