Questions
Syllabus
Qns. By Syllabus

Semester

Subject

Year

Tribhuwan University

Institute of Science and Technology

Model

Bachelor Level / Second Year / Fourth Semester / Science

Bachelors in Information Technology (BIT254)

(Network and Data Communications)

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.
Explain TDMA, FDMA and WDMA with necessary diagrams. Represent bit sequence 100101011 by the following waveform: NRZ-L, NRZ-I, Manchester, Differential Manchester[10]
2.
Explain leaky-bucket algorithm. Illustrate with an example. What are its advantages and disadvantages?[10]
3.
Explain the procedure for pure ALOHA. Highlight the vulnerable time of pure ALOHA. A pure ALOHA network transmits 200-bit frames on a shared channel of 200 kbps. What is the requirement to make this frame collision-free?[10]
Section B

Short Answers Questions

Attempt any Eight questions.
[8*5=40]
4.
Explain different layers of OSI [5]
5.
Differentiate between circuit switching and packet switching. What are their practical implications? [5]
6.
Briefly explain satellite network. Consider a noiseless channel with a bandwidth of 3400 Hz transmitting a signal with two signals. Calculate the maximum bit rate [5]
7.
Explain about ARP operation. [5]
8.
Describe user datagram format. List at least four ports used with UDP [5]
9.
Briefly explain recursive resolution, iterative resolution and caching [5]
10.
List one difference between open-loop and closed-loop congestion control. Explain acknowledgement policy and discarding policy [5]
11.
What is MAC-address? The message sequence is 11001000 and generator polynomial G(X) = $x^3 + x + 1$. Calculate the transmitted encoded frame [5]
12.
Write short notes on Attenuation and SNMP [5]