Answer the following problems in detail.

problem 1) Why does TCP/IP model have layers?

problem 2) What is the requirement of domain name system?

problem 3) What do you mean by port numbers?

problem 4) What services do port no. 80 and 21 indicate?

problem 5) What does IEEE 802 standard stand for?

problem 6) What is the function of IP protocol?

problem 7) describes the use of ICMP packets?

problem 8) What does PPP protocol stand for?

problem 9) Describe TCP/IP layered model describing functions of each layer.

problem 10) Describe the functioning of link layer.

problem 11) Describe the DNS message format.

problem 12) Describe IP addressing rules mentioning subnet masks as well.

problem 13) Describe Telnet and FTP applications.