If Source Computer Wants To Send HELLO Message To Destination Computer. How It Would Be Possible Using The Layering Structure OSI Model

If source computer wants to send HELLO message to destination computer. How it would be possible using the layering structure OSI Model

Q1. If the source computer wants to send HELLO message to the destination computer. How it would be possible using the layering structure OSI Model? (Note: Start procedure from Application Layer) Q2. Discuss the function of FCS in HDLC frame structure. Also, give different frame types in HDLC frame.