In my TCL script, I need to access the Call-ID that is sent as SIP sip header when I do a leg setup to start an outgoing leg.
 
The manual has examples on how to get this value for incoming SIP calls, but I haven't found the way to get this value when I'm initiating the outbound call.
 
I have tried:
 
                set foo [infotag get leg_proto_headers "Call-ID"]
 
but it the returning value is empty.
 
I have also tried using leg_outgoing_guid but the vale it returns is the exact same one as the leg_incoming_guid.
 
Thanks in advance for any help!

Yaw-Ming, thank you for your help.

I've tried using evt_proto_headers, which according to the manual, can only be used in the ev_notify, ev_subscribe_done, ev_unsubscribe_indication events.

As soon as I add the ev_notify event to my fsm, i start getting errors:

May 18 18:23:01.084: //-1/xxxxxxxxxxxx/SIP/Msg/ccsipDisplayMsg:
Sent:
SIP/2.0 500 Internal Server Error
...

Adding ev_subscribe_done it's never triggered.

Is there another way to retrieve the Call-Id sip header?