Question Paper: Computer Communication Networks : Question Paper Jun 2012 - Electronics & Communication (Semester 7) | Visveswaraya Technological University (VTU)
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## Computer Communication Networks - Jun 2012

### Electronics & Communication (Semester 7)

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) With a neat diagram, explain the TCP/IP reference model.(10 marks) 1 (b) Explain in detail, the cable TV network used for data transfer.(6 marks) 1 (c) Calculate the minimum time to download the one million bytes of information using each of the following technologies:
(i) V.32 modem
(ii) V.32 bia modem
(iii) V.90 modem
(4 marks)
2 (a) With a neat diagram of piggy backing in Go-Back-N ARQ protocol, explain the following:
(i) Frame structure of piggy backing
(ii) Types of events occurred in piggy backing
(10 marks)
2 (b) With a neat diagram, explain the different types of high level data link control (HDLC) frames.(6 marks) 2 (c) The following character encoding is used in a data link protocol:
A : 01000111 : B : 11100011 : FLAG : 01111110 : ESC = 111 00000. Show the bit sequence transmitted (in binary) for the four character frame : A B ESC FLAG when each of the following framing methods are used :
(i) Character count
(ii) FLag bytes with byte stuffing
(iii) Starting and ending flag bytes with bit stuffing
(4 marks)
3 (a) With a suitable flow diagram, explain CSMA/CD protocol and discuss the frame transmission time.(8 marks) 3 (b) Explain the following controlled access methods:
(i) Reservation
(ii) Polling
(iii) Token passing
(8 marks)
3 (c) Show that the throughput for the pure ALOHA is S=Ge-2G and maximum throughput Smax=0.184.(4 marks) 4 (a) With a neat diagram, explain 802.3 MAC frame format. (10 marks) 4 (b) Explain the following standard ethernet physical layer implementations.
(i) 10 base 5 : thick ethernet
(ii) 10 base 2 : thin ethernet
(iii) 10 base T : twisted pair ethernet
(iv) 10 base F: fiber ethernet.
(10 marks)
5 (a) Explain the following in brief:
(i) Passive hubs
(ii) Active hubs
(iii) Bridges
(iv) Router
(v) Gateway.
(10 marks)
5 (b) Explain virtual LAN system and how the membership is allocated in the V-LAN system.(10 marks) 6 (a) What are the difference between classful and classless addressing?(5 marks) 6 (b) What is network address translation (NAT)? Explain in brief.(5 marks) 6 (c) Draw the IPV4 datagram formats and explain its field.(10 marks) 7 (a) Explain the detail, the distance vector routing algorithm.(10 marks) 7 (b) Explain three different forwarding techniques.(10 marks) 8 (a) Explain in detail, user datagram protocol, UDP.(10 marks) 8 (b) Describe DNS in the internet.(10 marks)