localhost*CLI> core show version 
Asterisk 16.6.1 built by root @ localhost.localdomain on a x86_64 running Linux on 2019-10-18 02:34:50 UTC


1. Dialplan
1.1. extensions.conf
1	[ari-test]
2	exten => 111,1,NoOp()
3	 same =>     n,Progress()
4	 same =>     n,Stasis(ari-test,incoming,${EXTEN},${CALLERID(ani)})
5	 same =>     n,Hangup()

1.2. sip.conf
1	[1000]
2	context=ari-test
3	...
4
5	[3000]
6	context=ari-test
7	...


2. Python
"dial-early.py" file attached separately.


3. dial-early.py in action
Dial
dialstatus = []
dialstatus = [RINGING]
dialstatus = [BUSY]
<SIP/1000-0000000d> has left the application
safe_bridge_destroy


4. How to test
4.1 Set to busy on the callee(SIP/3000).
4.2 Press 111 on the caller(SIP/1000).
4.3 The scripts dial to the callee(SIP/3000) automatically.


5. Description
The caller hear a busy tone, but the call is out.
"StasisEnd" event occurs on inbound channel by asterisk if outgoing channel is "busy" or "decline".
You can no longer control the inbound channel.