freeswitch/conf/autoload_configs/switch.conf.xml

<configuration name="switch.conf" description="Core Configuration">

  <cli-keybindings>
    <key name="1" value="help"/>
    <key name="2" value="status"/>
    <key name="3" value="show channels"/>
    <key name="4" value="show calls"/>
    <key name="5" value="sofia status"/>
    <key name="6" value="reloadxml"/>
    <key name="7" value="console loglevel 0"/>
    <key name="8" value="console loglevel 7"/>
    <key name="9" value="sofia status profile internal"/>
    <key name="10" value="sofia profile internal siptrace on"/>
    <key name="11" value="sofia profile internal siptrace off"/>
    <key name="12" value="version"/>
  </cli-keybindings> 
  
  <settings>
    <!--Colorize the Console -->
    <param name="colorize-console" value="true"/>
    <!--Most channels to allow at once -->
    <param name="max-sessions" value="1000"/>
    <!--Most channels to create per second -->
    <param name="sessions-per-second" value="30"/>
    <!-- Default Global Log Level - value is one of debug,info,notice,warning,err,crit,alert -->
    <param name="loglevel" value="debug"/>
	<!-- The min_dtmf_duration specifies the minimum DTMF duration to use on 
	     outgoing events. Events shorter than this will be increased in duration
		 to match min_dtmf_duration. You cannot configure a dtmf duration on a 
		 profile that is less than this setting. You may increase this value,
		 but cannot set it lower than 400. This value cannot exceed 
		 max_dtmf_duration. -->
    <!--<param name="min_dtmf_duration" value="400"/>-->
	<!-- The max_dtmf_duration caps the playout of a DTMF event at the specified
	     duration. Events exceeding this duration will be truncated to this
		 duration. You cannot configure a duration on a profile that exceeds
		 this setting. This setting can be lowered, but cannot exceed 192000. 
		 This setting cannot be set lower than min_dtmf_duration. -->
    <!--<param name="max_dtmf_duration" value="192000"/>-->
	<!-- The default_dtmf_duration specifies the DTMF duration to use on
	     originated DTMF events or on events that are received without a
		 duration specified. This value can be increased or lowered. This
		 value is lower-bounded by min_dtmf_duration and upper-bounded by
		 max_dtmf_duration. -->
    <!--<param name="default_dtmf_duration" value="2000"/>-->
    <!--
         If you want to send out voicemail notifications via Windows you'll need to change the mailer-app
         variable to the setting below:
     
       <param name="mailer-app" value="msmtp"/>
 
         Donot change mailer-app-args.
         You will also need to download a sendmail clone for Windows (msmtp). This version works without issue:
         http://msmtp.sourceforge.net/index.html. Download and copy the .exe to %winddir%\system32.
         You'll need to create a small config file for smtp credentials (host name, authentication, tls, etc.) in
         %USERPROFILE%\Application Data\ called "msmtprc.txt". Below is a sample copy of this file:
 
         ###################################
         # The SMTP server of the provider.
         account provider
         host smtp.myisp.com
         from john@myisp.com
         auth login
         user johndoe
         password mypassword
 
         # Set a default account
         account default : provider
       ###################################
         
 -->    
    <param name="mailer-app" value="sendmail"/>
    <param name="mailer-app-args" value="-t"/>
    <param name="dump-cores" value="yes"/>
    <!--RTP port range -->
    <!--<param name="rtp-start-port" value="16384"/>-->
    <!--<param name="rtp-end-port" value="32768"/>-->
    <param name="rtp-enable-zrtp" value="true"/>
  </settings>

</configuration>