ASSIGNMENT

1) What is a network protocol ? Why do we need OSI Model ?

2) Consider different activities related to email: al: Checking an email from web browser a2: Sending an email from a mail client to a mail server a

3: Downloading an email from mailbox server to a mail client What are the application layer protocols used for alia2,02_ 3)

In TCP, does FIN segment close a connection in only one direction or both directions? What type of flag can be used to close the communication in both directions? What is the minimum size of a UDP user datagram? What is the maximum size of a UDP user datagram?

4) What is a 3-way handshake in transport layer? Briefly explain the congestion control in transport layer.

5) How do the signals carried in copper and fiber optic differ?