Computer Networks 1 - Jun 2014

Computer Science Engg. (Semester 5)

TOTAL MARKS: 100
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any four from the remaining questions.
(3) Assume data wherever required.
(4) Figures to the right indicate full marks. 1 (a) What is data communication?What are the four fundamental characteristic? With a neat diagram ,explain the components of data communicating system.(8 marks) 1 (b) Assume that five devices are connected in a mesh topology.How many cables are needed? How many ports are needed for each device?(2 marks) 1 (c) With a neat diagram, explain the functionalities of each layer of OSI reference model.(10 marks) 2 (a) Explain the different causes for transmission impairments during signal trasmiission through media(6 marks) 2 (b) Define bandwidth . A periodic signal has bandwidth of 20Hz.The highest frequecy in 60 Hz .What is the lowest frequency?Draw the spectrum if the signal contain all frequncies of the same amplitude.(4 marks) 2 (c) What is line coding ?Describe and represent the information sequence "101000110" using biphase and bipolar schemes(10 marks) 3 (a) What is multiplexing ? Explain with a neat diagram FDM.(8 marks) 3 (b) What is spread spetrum? Explain with an example direct sequence spred spectrum(8 marks) 3 (c) With a neat diagram .Explain how message can be sent from one system to another using datgaram networks(8 marks) 4 (a) Define hamming distance/ expalin simple parity check code C(5,4) with d_min-2 .How many bits can be corrected ?(6 marks) 4 (b) Find the code word e(x),using CRC for the information d(x)=x³ +1 with generator polynomial t(x)=x^3+x+1(8 marks) 4 (c) Explain with an example .The computaton of internet checksum.List the step undertaken by the sender and receiver for error detection(6 marks) 5 (a) Why bit stuffing and byte stuffing are needed? Explain them ,With example(6 marks) 5 (b) With neat figures ,explain briefly?
GO-back n
Selective repeat ARQ protocol(10 marks) 5 (c) Expalin the frame formate of PPP protocol(4 marks) 6 (a) Describe CSMA/CD protocol ,With neat floww diagram(6 marks) 6 (b) What is channelixation ?Explain CODE division multiple access,With an example (8 marks) 6 (c) Discuss 802.3 MAC frame formate and frame length(6 marks) 7 (a ) Explain the different Types of addressing mechanism in IEEE 802.11(6 marks) 7 (b) With neat diagram ,Explain layers of bluetooth.(6 marks) 7 (c) What is bridge? Explain with an example the bridge learning and forwarding process transparent bridge.(8 marks) 8 (a) Explain the following fields in IPV4 packet headr:
Identifiaction
Flags
Framention offset(6 marks) 8 (b) What is NAT ?How can NAT help in deplation with a neat diagram(6 marks) 8 (c) What is the need to change from IPV4 to IPV6? Write IPV^ basic header and describe fields(8 marks)