Computer Communication Networks - Dec 2014

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.

Answer any four of the following:

1 (a) Compare the performance characteristics of co-axial, twisted pair and fiber optic transmission media.(5 marks) 1 (b) Exlain various LAN topologies.(5 marks) 1 (c) What is meant by 'blocking' in switched networks? Bring out merits and demerits of a single stage space division switch.(5 marks) 1 (d) Explain general principles of congestion control in Packet switching networks.(5 marks) 1 (e) Explain Berkley API.(5 marks) 2 (a) Compare circuit switching, packet switching and message switching.(10 marks) 2 (b) What is Flow Control? Explain Sliding window flow control with neat diagrams. How is the window size Determined?(10 marks) 3 (a) Explain in detail OSI model.(10 marks) 3 (b) What is DSL technology? Explain various DSL technologies and compare them.(10 marks) 4 (a) Draw the block diagrams of SONET and explain its operation. Also explain SONET frames. Explain the functional layers of SONET.(10 marks) 4 (b) With reference to HDLC, Explain the following -
i) various frames of HDLC.
ii) Data transfer modes.
iii) Data trasparency.
iv) Unbalanced and balanced configuration
v) Piggy backing and Pipelining.(10 marks) 5 (a) Explain different ARQ techniques in detail and state which ARQ technique is preferred for noisy links? And why?(8 marks) 5 (b) Design a three stage space division switch with N=15, n=5, K=3 and show how Blocking occurs in this. Derive the condition required to make this switch non-Blocking.(6 marks) 5 (c) Discuss various Routing strategies for packet switching networks.(6 marks) 6 (a) Explain the following network connecting devices:-
i) switches
ii) routers
iii) gateway
iv) hub
v) bridge(10 marks) 6 (b) Explain the MAC sublayer Frame format for IEEE802 Reference? Explain Fast Ethernet specifications. Also explain CSMA-CD in detail.(10 marks)

Write short notes on:

7 (a) ISDN.(5 marks) 7 (b) Sub-netting and Super-netting with an example.(5 marks) 7 (c) IP utilities.(5 marks) 7 (d) Token Re-insertion Strategies.(5 marks)