Tribhuwan University

Institute of Science and Technology

2079

Bachelor Level / Second Year / Fourth Semester / Science

B.Sc in Computer Science and Information Technology (CSC263)

(Computer Networks)

Full Marks: 60

Pass Marks: 24

Time: 3 Hours

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

The figures in the margin indicate full marks.

Section A

Long Answers Questions

Attempt any TWO questions.
[2*10=20]
1.
What is protocol? Explain each layer of OSI model in detail.[10]
2.
Differentiate error detection with error correction. Explain CRC (Cyclic Redundancy Check) method for error detection with a suitable example.[10]
3.
Explain distance vector routing with example.[10]
Section B

Short Answers Questions

Attempt any Eight questions.
[8*5=40]
4.
Why do we need network topology? Explain star topology along with its merits and demerits. [5]
5.
Define Protocol. Why do we need standards? [5]
6.
What is circuit-switched network? Explain phases during communication in a circuit-switched network? [5]
7.
What is a virtual circuit network? Explain frame relay as a virtual circuit-wide area network. [5]
8.
Why TCP is called a connection-oriented and reliable protocol? Differentiate TCP with UDP. [5]
9.
Explain architecture of WWW. What is URL? [5]
10.
Explain in brief about software defined network? What are its features? [5]
11.
Write short notes on (any two): a. Protocol and standards b. Switch c. Checksum [5]
12.
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? [5]