freeswitch/conf/vanilla/autoload_configs/smpp.conf.xml

<configuration name="smpp.conf" description="SMPP client and server Gateway">
  <gateways>
    <gateway name="example.com">
      <params>
	<param name="host" value="example.com"/>
	<param name="port" value="2775"/>
	<param name="debug" value="1"/>
	<param name="profile" value="default"/>
	<param name="system_id" value="username"/>
	<param name="password" value="password"/>
	<param name="system_type" value="remote_smpp"/>
      </params>
    </gateway>
  </gateways>
</configuration>