Explain the functions or purposes of the seven layers of the OSI Reference Model from the top ( Layer 7 ) to the bottom ( Layer 1 ).

I.Name and briefly explain the functions or purposes of the seven layers of the OSI Reference Model from the top ( Layer 7 ) to the bottom ( Layer 1 ).

II. Explain, specifically, what is accomplished at each of the following Layers of the OSI Reference Model:
A. Transport Layer
B. Network Layer
C. Data Link Layer

III.Explain the structure and importance of a properly designed cable plant.

IV. Briefly explain each of the following;
A. Analog Signaling
B. Digital Signaling
C. Simplex transmission
D. Half-Duplex transmission
E. Full- Duplex transmission
F. Multiplexing
G. Physical Topology
H. Logical Topology
I. Star Topology
J. Ring Topology
K. Circuit Switching
L. Packet Switching