Computer Networks 1 - Jun 2013
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) Explain OSI refernce model(10 marks) 1 (b) Explain Categories of network and differentiate between them(10 marks) 2 (a) Reprsent the given sequence 01001110 in unipolar .NRZ-L ,manchester AMI, pseudotnery?(6 marks) 2 (b) The loss in a cable deined in debels/km(db/km).If the signal at the beginning of a cable with -3db/km has a power of 3 mW.What is the power of the signal at 5km?(6 marks) 2 (c) Explain the PCM encoder?(8 marks) 3 (a) Explain frequncy hopping spread spectrumm (FHSS).(10 marks) 3 (b) Four 1Kbps connection are multitasking together .A unit is 1 bit .Find
The duration of 1bit before ultitaskking
The transmission rate of the link
The duration of a tiem slot
The duration of a frame(5 marks) 3 (c) differentiate between circuit switched ,Datagarm networks and virtual circuit network(5 marks) 4 (a) Explain structure of encoder and decoder for hamming code(8 marks) 4 (b) find the codeword using CRC given dataword 1001 and genretor 1011(6 marks) 4 (c) What is internet chsecksum ?With an example ,list the step undertaken by the sender and receiver for error detection(6 marks) 5 (a) Explain stop-and -wait ARQ protocol with neat diagram(8 marks) 5 (b) What is framing? Explain bit and character stuffing with an example(4 marks) 5 (c) Write a shors notes on HDLC.(8 marks) 6 (a) Explain CDMA(6 marks) 6 (b) a slotted ALOHA network transmit 200 bit frame using a shared channel with 200 Kbits/sec bandwidth .Find throught if system produces
frames/sec(6 marks) 6 (c) Explain 802.3 MAC frame formate(8 marks) 7 (a ) Explain the architecture of IEEE 802.11.(10 marks) 7 (b) Explain connecting devices(10 marks) 8 (a) Draw IPV4 header format and explain (8 marks) 8 (b) A ISP is granted a block of address starting with 220.127.116.11/16(655.536 address). The ISSP needs to distribute these addressing to 3 groups of customers
First group has 64 customers each needs 128 address
Second group has 28 customers each needs 64 address
Design the subblock and findout .How many adresses are still available after teh allocation?(7 marks) 8 (c) Compare between IPV4 and IPV6(5 marks)