a) Describe each of the seven layers of the ISO/OSI model. For each layer explain its function and provide examples of protocols and devices associated with it. (Unit 1)

b) What is Shannon's Theorem and what does it state about the maximum data rate of a communication channel? Establish a relationship between channel capacity, bandwidth and signal-to-noise ratio (SNR) according to Shannon's Theorem. (Unit 1)

a) What do you understand by transmission media. Give the difference between Guided and Unguided media. (Unit 1)

b) Why is error control necessary in data communication? Describe the methods used for error detection and correction in the Data Link Layer. (Unit 2)

a) Calculate the CRC checksum for a data word represented by the polynomial $D(x)=x^{5}+x^{4}+x^{2}+1$ and a CRC polynomial $C(x)=x^{3}+x+1.$ (Unit 2)

b) How does ALOHA handle contention among multiple devices trying to access the shared channel? Give the advantages and limitations of the pure ALOHA protocol. (Unit 2)

a) Describe the key features and characteristics of the IEEE 802.3 Ethernet standard. (Unit 3)

b) What is a network switch and what role does it play in computer networking? How does a switch build and maintain its MAC address table? (Unit 3)

a) What are the primary design issues in the Network Layer and also discuss the main functions performed by the Network Layer? (Unit 3)

b) Explain the concept of Shortest Path Routing with suitable example. Also discuss the advantages and limitations of Shortest Path Routing. (Unit 4)

a) Explain the role of each layer in the TCP/IP protocol stack with suitable layered architecture. (Unit 4)

b) What is ICMP? Describe the role of ICMP messages in network communication. What types of information do ICMP messages convey? Explain. (Unit 4)

a) What is the Domain Name System (DNS) and what role does it play in computer networking? Explain how DNS translates domain names to IP addresses and vice versa. (Unit 5)

b) What is load shedding and how does it relate to congestion control? Discuss some techniques used for load shedding in the Transport Layer. (Unit 5)

Write a short note on any two:

a) Circuit, Packet and Message Switching (Unit 1)

b) HDLC (Unit 2)

c) Router and Gateways (Unit 3)

d) Connection establishment and release (Unit 5)