freeswitch/conf/minimal/vars.xml

<include>
  <X-PRE-PROCESS cmd="set" data="global_codec_prefs=PCMU,PCMA"/>

  <!-- NOTE: CHANGE THIS BEFORE USE -->
  <X-PRE-PROCESS cmd="set" data="xml_rpc_password=worksnot"/>

  <X-PRE-PROCESS cmd="set" data="internal_sip_port=5060"/>
  <X-PRE-PROCESS cmd="set" data="external_sip_port=5080"/>
</include>