MCS-042 Data Communication and Computer Network

Title Name	MCS-042 Solved Assignment 2019-20
University	IGNOU
Service Type	Solved Assignment (Soft copy/PDF)
Course	MASTER OF COMPUTER APPLICATIONS(MCA)
Language	ENGLISH
Semester	MCA/ASSIGN/SEMESTER-IV
Session	2019-20
Short Name	MCS-042
Assignment Code	MCA(IV)/042/Assignment/2019-20
Product	Assignment of MCA 2020 (IGNOU)
Price	Rs. 20
Last Date of Submission	15th October, 2019 (For July, 2019 Session) 15th April, 2020 (For January, 2020 Session)

This assignment has thirteen questions. Answer all questions. Rest 20 marks are for viva voce. You may use illustrations and diagrams to enhance the explanations. Please go through the guidelines regarding assignments given in the Programme Guide for the format of presentation.

Q1. (a) What is the need of modulating a signal? Will it be a right approach to send the
information as the signal itself? (4 Marks)
(b) Explain techniques used in digital to analog modulation with the help of diagram (5 Marks)

Q2. (a) Discuss the different approaches to circuit switching? Why it is suitable for voice
Transmission? What are its limitations? (5 Marks)
(b) How does multistage switching overcome these limitations? (3 Marks)
Q3. A bit string 011100111110001110 needs to be transmitted at the data link layer. What
is the string actually transmitted after bit stuffing? (2 Marks)
Q4. (a) Define checksum and write the algorithm for computing the checksum? (5 Marks)
Q5. Define flow error control and piggybacking concepts. Show the operation of Stop &
Wait ARQ with the help of an illustration. Also illustrate the outcome of Stop & Wait
ARQ in the following scenarios. (6 Marks)
(i) When ACK is lost
(ii) When Frame is lost
(iii) When ACK timeout occurs
Q6. (a) How does MACAW work? Show diagrammatically. What are the added features
in MACAW compared to MACA ? (5 Marks)
(b) What are the advantages of frame fragmentation in wireless network? Explain. (4 Marks)
Q7. How does a bridge operate in different LAN environments? What are the
problems encountered in building a bridge between the various 802 LANs ? Discuss. (5 Marks)
Q8. Write Dijkstra and Bellman Fords shortest path routing algorithms and make a
comparison between the two algorithms. (6 Marks)
Q9. (a) Discuss general principle of congestion control and the mechanisms used in
congestion control in packet switched network . (6 Marks)
(b) Explain the implementation of token bucket traffic shaper with the help of a diagram? (5 Marks)
Q10. Explain with the help of an example and a diagram how the congestion controls
algorithm (slow start algorithm) work at transport layer. (5 Marks)
Q11. (a) Define digital signature and explain its benefits. (4 Marks)
(b) What kind of a model is being used in India to provide public key infrastructure
related services. (I.e. management of public keys). Elaborate. (5 Marks)
Q12. Discuss the implementation of Kerberos mechanism. (5 Marks)