conference_set_auto_outcall not working with proxy server. I am calling application from lua with following code. Suppose 167 is sip phone no.

session:execute("conference_set_auto_outcall", "sofia/gateway/Kamailio/167")

Gateway is defined in external.xml

<gateway name="Kamailio">
         <param name="extension" value="conference"/>
         <param name="expire-seconds" value="125"/>
         <param name="register-transport" value="udp"/>
         <param name="proxy" value="xyz.com"/>
         <param name="register" value="false"/>
         <param name="caller-id-in-from" value="true"/> 
         <param name="username" value="not-used"/>
         <param name="password" value="not-used"/>
    </gateway>

Error:

2015-07-03 16:06:50.193203 [NOTICE] switch_core_session.c:1633 Session 35 (sofia/external/167) Ended 2015-07-03 16:06:50.193203 [NOTICE] switch_core_session.c:1637 Close Channel sofia/external/167 [CS_DESTROY] 2015-07-03 16:06:50.193203 [DEBUG] switch_core_state_machine.c:626 (sofia/external/167) Running State Change CS_DESTROY 2015-07-03 16:06:50.193203 [DEBUG] switch_core_state_machine.c:636 (sofia/external/167) State DESTROY 2015-07-03 16:06:50.193203 [DEBUG] mod_sofia.c:323 sofia/external/167 SOFIA DESTROY 2015-07-03 16:06:50.193203 [DEBUG] switch_core_state_machine.c:111 sofia/external/167 Standard DESTROY 2015-07-03 16:06:50.193203 [DEBUG] switch_core_state_machine.c:636 (sofia/external/167) State DESTROY going to sleep 2015-07-03 16:06:50.193203 [ERR] mod_conference.c:8469 Cannot create outgoing channel, cause: NORMAL_TEMPORARY_FAILURE 2015-07-03 16:06:50.193203 [DEBUG] switch_ivr_originate.c:2079 Parsing global variables