Symptom:
Busy Message indication not showing while declining a call

Conditions:
Steps to reproduce :
1.	Create a site with unified CM installed in it . Register 99XX IP phone A and DX650 IP phone B 
2.	Make call from 99XX IP phone A , DX650 IP Phone will ring 
3.	Decline the call in DX650 . 
4.	99XX IP phone will be in busy state .
Problem description: When the call is declined in DX650 IP phone in 99XX IP Phone BUSY message indication should be shown . But the message is does not appears in 99XX IP Phone .
Expected Behaviour: While declining  a call 99XX IP phone should show the BUSY message .
Environmental Matrix: 
CUCM: 10.5.0.99834-1 
99XX IP Phone: SIP 9971. 9.4.1.9