From FreeSWITCH Wiki

Introduction

It is included in mod_spandsp.

Loopback/ channels: T.38 pass-through can *NOT* be used with loopback/ channels.

Usage Cases

<extension name="tdm_to_sip">
 <condition field="destination_number" expression="^1234$">
   <action application="t38_gateway" data="peer"/>
   <action application="bridge" data="sofia/<profile>/<extension>"/>
 </condition>
</extension>

<extension name="sip_to_tdm">
 <condition field="destination_number" expression="^1235$">
   <action application="t38_gateway" data="self"/>
   <action application="bridge" data="freetdm/<profile>/<extension>"/>
 </condition>
</extension>

<extension name="t38_passthru">
 <condition field="destination_number" expression="^1236$">
   <action application="export" data="t38_passthru=true"/>
   <action application="bridge" data="sofia/<profile>/<extension>"/>
 </condition>
</extension>

Sofia profile parameters

t38-passthru = true|false|once

See Also

• mod_spandsp