Consider a scenario where a video call is made through Whatsapp

from your cell phone and the receiver is your friend's cell phone

over the Internet in real time.

i$)$ Illustrate the same from connection establishment phase to

connection tear down phase in normal case. $($Include the required

protocols and message stream$)$ with neat sequence diagram.

ii$)$ Assume a scenario if you are unable to track your friend

$($callee$)$ then detail the steps taken in exchanging of video with a

neat sequence diagram.