Data Communication and Networking — DU B. Voc – Web Designing Previous Year Question Papers

Parts of a question must be answered together. 1 (a) Differentiate between simplex, Half Duplex, and Full Duplex with one (3) exanple each. (b) Define Ip address and subnet mask. Give one example [ (3) (c) Differentiate between Guided and Unguided Transmission Media with (3) (d) Find the minimum bandwidth needed if 5 channels (each 500 kHz wide) are multiplexed with 10 kHz guard bands between them (e) Write three differences betwee`n osl and TCP/IP Model. (3) © Given the data bit stream 01111101111110111101111, Add Flag (3) bits and perform bit stufflng. Write the final transmitted bit stream. The flag bits is 0 1 1 1 1 1 1 0 . (g) Which layer(s) in the OSI Model performs the following operations? (3) i) Synchronization ii) Encryption iii) Mail Services (7) Explain the difference between synchronous and asynchronous (3) What is frequency division multiplexing (FDM)? Explain its working. (3) (j) What is CSMA/CD and how does it work in Ethernet? (3) 2 (a) Calculate the original 8-bit data from the received 12-bit Hamming code: (5) 101101011110 (odd parity assumed; max one-bit error). (b) Consider a communication system with a bandwidth of 5 kHz and a signal- (5) to-noise ratio (SNR) of 31 dB. Using Nyquist's Theorem, calculate the maximum data rate (in bps) that can be transmitted over the channel without any error. (c) Consider a situation where a company needs a network with high reliability (5) and tault tolerance. Which topology would you recommend? Draw the network topology and discuss its advantages and disadvantages? What is the key difference between bus and star topology? (a) Given a data word 10101101 and a generator polynomial ** + x + 1, (5) compute the transmitted CRC code. (0) Diferentiate between Circuit switching and packet switching. Why is (5) packet switching more resilient to network failures compared to circuit switching? (c) Briefly explain the following CSMA protocols: (5) (1) 1-persistent p-persistent (a) The following character encoding is used in a data link protocol: (5) A: 01000111 ; B: 11100011 ; Flag: 01111110; ESC: 11100000 show the bit sequence transmitted (in binary) for the four-character frame: A BESC FLAG A ESC when each of the following framing methods are used: 1. Character Count il. Flag bytes with Byte Stuffing iii. Starting and ending flag bytes, with bit stuffing (b) Draw and explain the full architecture of the OSI reference model. Describe (5) the function of each layer in OSI reference model. (c) Consider the following network with the indicated link cost. Using shortest path Algorithm, find the shortest path from source node A to all other nodes: 5 (a) I. Consider a noiseless chamel with a bandwidth of3000 Hz transmitting (2+3) a signal with four signal levels. Calculate the maximum bit rate of the charmel. 11. Define the temi `bandwidth' in the context of network communication.