1 (a) Compare and contrast between analog and digital communication.

(b) What are layers in the OSI Model? Discuss the major functions and services of each layer?

(c) How Cyclic Redundancy Check (CRC) is used in error-detection? Describe using an ex, where Message bits M=1010101010 and Generator bits G=10001.

(d) What is the requirement of multiplexing channels? What types of techniques are used for multiplexing channels?

2(a) Describe working of Distance Vector Routing with the ex. Also, discuss the Count to Infinity Problem.

(b) What are different transmission media available? prepare advantage and disadvantages of each.

(c) Differentiate between packet switching and Circuit Switching.

(d) Describe the process of sampling used digital communication.

3(a) Why does multiple accesses required in LAN technologies? Compare various multiple accesses techniques.

(b) Compare throughput of pure and slotted ALOHA.

(c) describe advantages and disadvantages of Bus, Ring and Mesh topologies.

(d) Why does ATM use small fixed size cell? Justify the answer.

4(a) Compare and contrast flow control and error control in the data transmission. Also, suggest the solutions for each.

(b) Suppose two prime numbers p=251 and q= 257. Use RSA algorithm to compute encryption key and decryption key. prepare all intermediate steps in calculation.

(c) prepare down the steps used in connecting two computers by cross-over cable?

(d) prepare down the disadvantages of CDMA in wireless communication.