Tribhuvan University

Institute of Science and Technology

2079

Bachelor Level / fourth-semester / Science

Computer Science and Information Technology( CSC263 )

Computer Networks

Full Marks: 60 + 20 + 20

Pass Marks: 24 + 8 + 8

Time: 3 Hours

Candidates are required to give their answers in their own words as far as practicable.

The figures in the margin indicate full marks.

Long Answer Questions

Attempt any two questions (2 x 10 = 20)

1

What is protocol? Explain each layer of OSI modal in detail.

2

Differentiate error detection with error correction. Explain CRC (Cyclic Redundancy Check) method for error detection with a suitable example.

3

Explain distance vector routing with example.

Short Answer Questions

Attempt any Eight questions (8 x 5 = 40)

4

Why do we need network topology? Explain star topology along with its merits and demerits.

5

Define Protocol. Why do we need standards?

6

Write the subnet ID and broadcast address of each subnet if you divide a class C network (192.168.3.0 – 192.168.3.255) into 4 different subnets. What is the new subnet mask?

7

What is circuit-switched network? Explain phases during communication in a circuit-switched network?

8

What is a virtual circuit network? Explain frame relay as a virtual circuit-wide area network.

9

Why TCP is called a connection-oriented and reliable protocol? Differentiate TCP with UDP.

10

Explain architecture of WWW. What is URL?

11

Explain in brief about software defined network? What are its features?

12

Write short notes on (any TWO)

  1. Protocol and standards
  2. Switch
  3. Checksum