[asterisk-users] CallerID inconsistently presented through ISDN/cellular networks

[giovanni.v]

Il 09/11/2011 17.37, Richard Mudgett ha scritto:
> You would then use
> the DAHDISendCallreroutingFacility application*before*  you answer
> the call to forward/deflect the incoming call back to the network.

I think "Answer" makes no sense at all because the network will redirect 
then continue to cancel the preceding call setup.

ETSI Call Deflection/Rerouting message flow:

                                               Deflection
Caller        Carrier                   PBX   destination
   |---SETUP----->|                      '          '
                  |----SETUP------------>|          '
                  |<---CALL PROCEEDING---|          '
                  |<---FACILITY+ --------|          '
                  |----DISCONNECT------->|          '
                  |<---RELEASE-----------|          '
                  |----RELEASE COMPLETE->|          '
                  |----SETUP----------------------->|


This will also require this settings on the dahdi channel?
facilityenable=yes
transfer=yes
??

Also, according to this document http://www.asterisk.org/node/48611 
seems that DAHDISendCallreroutingFacility() doesn't return anything so 
how we can test if the command was successful or refused?