Computer Communication Networks - Dec 2011

Electronics Engineering (Semester 7)

TOTAL MARKS: 80
TOTAL TIME: 3 HOURS (1) Question 1 is compulsory.
(2) Attempt any three from the remaining questions.
(3) Assume data if required.
(4) Figures to the right indicate full marks. 1 (a) Explain the property of data transparency with reference to HDLC.(5 marks) 1 (b) Differentiate between in-band signaling and out-band signaling.(5 marks) 1 (c) What are the conditions to be satisfied for a valid CRC generator polynomial. Draw the block diagram of CRC generator.(5 marks) 1 (d) Explain how fast Ethernet differs from 10 Base T.(5 marks) 2 (a) Derive the transmission efficiency of Go back N ARQ. State effect of bit error rate and delay bandwidth product on transmission efficiency.(10 marks) 2 (b) Explain the spanning tree algorithm with respect to frame forwarding, address learning and loop resolution.(10 marks) 3 (a) Identify the address class of following IP addresses :
1. 200.58.20.165
2. 128.167.23.20.
Also perform CIDR aggregation on the following :
128.56.24.0| 22 and 200.96.87.0|22
(10 marks) 3 (b) What is the essential difference between Dijkstra's algorithm and Bellman ford algorithm? Explain these algorithms in brief.(10 marks) 4 (a) Error control procedures are specified in each layer of OSI model. Indicate at the layers at which the following errors might occur:
(i) Noise on transmission link converts 0 bit to 1
(ii) A packet is routed to wrong destination.
(iii) A packet switching network delivers a data unit to a terminal attached to it out of sequence.
(iv) A printer printing halfway through a line is suddenly commanded by mistake to return to the beginning of the line.
(v) During half duplex mode session the transmitting user starts receiving data from the user at other end.
(10 marks) 4 (b) Sketch non -blocking switches with N =32 and group size of n= 4 for a 3 stage space division switch and a TST switch. Which is a better option? Why?(10 marks) 5 (a) List categories of UTP cables. How is noise interference minimized in twisted pair?(5 marks) 5 (b) What is delay distortion with respect to transmission medium? How it can be corrected?(5 marks) 5 (c) Explain ADSL with respect to channel configurations and modulation technique.(10 marks) 6 (a) Distinguish between implicit congestion signaling and explicit congestion signaling. Discuss three general approaches for explicit congestion signaling.(10 marks) 6 (b) Distinguish between following token insertion strategies
(i) i. Single token operation.
(ii) ii. Multiple token operation.
(iii) Single frame operation.(10 marks)

write a short note

7 (a) SONET(5 marks) 7 (b) Berkeley API(5 marks) 7 (c) ARQ techniques(5 marks) 7 (d) ISDN(5 marks)