make asterisk call implementation

new interface.conf (add remove ports by admin)

call to multiple endpoints (extensions)

trace with layers and filters
 - layer 1 and 2 state changes and messages
 - layer 3 isdn trace, process ids
 - messages between port, endpoint and call
 - port hunt and channel selection
 - dialing / routing
 - application process (action)
 - bchannel control (tones, dsp, filter, activation/deactivation)

avoid disconnect-collision (release if disconnect from both sides)

display message during nothing/play

Port -> Channel
Call -> Link



old stuff....

NOTE: check CENTREX

durchstellen mit disconnect
durchstellen mit keypad
ruf bei CFP gibt besetzt, wenn teilnehmer intern besetzt ist.
short ring
sleep relaxed
auto pick
alarm clock (timer)
sonderwahlton
facility: diversion, 3pty, ...


