freeswitch/conf/vanilla/autoload_configs/acl.conf.xml

<configuration name="acl.conf" description="Network Lists">
  <network-lists>
    <!--
	 These ACL's are automatically created on startup.

	 rfc1918.auto  - RFC1918 Space
	 nat.auto      - RFC1918 Excluding your local lan.
	 localnet.auto - ACL for your local lan.
	 loopback.auto - ACL for your local lan.
    -->

    <list name="lan" default="allow">
      <node type="deny" cidr="192.168.42.0/24"/>
      <node type="allow" cidr="192.168.42.42/32"/>
    </list>

    <!--
	This will traverse the directory adding all users
	with the cidr= tag to this ACL, when this ACL matches
	the users variables and params apply as if they
	digest authenticated.
    -->
    <list name="domains" default="deny">
      <!-- domain= is special it scans the domain from the directory to build the ACL -->
      <node type="allow" domain="$${domain}"/>
      <!-- use cidr= if you wish to allow ip ranges to this domains acl. -->
      <!-- <node type="allow" cidr="192.168.0.0/24"/> -->
    </list>

  </network-lists>
</configuration>