[Asterisk-Dev] IAX2 Hangup Cause

[reseaux]

Dear List
        im try to look if IAX2 protocol is able to transport an hangup cause 
from a TDM PRI line, as i can see from this link 
http://www.cornfed.com/iax.pdf it support only few message like 
congestion,busy,call progress, answer,ring,ringing but i cannot transport the 
Cuase of PRI hangup some idea. 
IF i use the send text feature of IAX2 between 2 * Box? I can receive this 
text? I have try but without success..
I design my scenario:

        Site A (AstGateway)                                                     
Site B (AstGateway)
Incoming->TDM-> IAX2 |-------|Hangup Cause|------>| IAX2->TDM -> Termination

Thanks for possible help & tips
Dimitri