Hi,
I programatically composed a SIP Notify MWI message and send to phone IP Adress. To turn on the Light I specify "Messages-Waiting: yes" and to turn off the Light I specify "Messages-Waiting: no". UDP Port 5060 was used and seems to be working.
Details of SIP MWI messages : http://www.ietf.org/rfc/rfc3842.txt
Thank You.,
