Computer Communication Networks - Dec 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) Describe the ISO OSI reference model of a computer network. Discuss the function of each layer.(10 marks) 1 (b) Describe the SS7 service and its relation to the telephone network.(5 marks) 1 (c) Distinguish between a DSL modem and a DSLAM.(5 marks) 2 (a) Differentiate between character stuffing and bit stuffing with examples.(5 marks) 2 (b) Explain different HDLC frames.(5 marks) 2 (c) What are sliding window protocols? Explain Go-Back-N protocol for Noisy channel.(10 marks) 3 (a) Compare pure ALOHA with slotted ALOHA. What are the reasons for poor channel utilization in ALOHA system? How the same is improved in CSMA.(8 marks) 3 (b) Discuss the concepts of
(i) 1-persistent CSMA
(ii) Non-persistent CSMA(8 marks) 3 (c) Explain the working of CSMA/CD. Suppose a point to point link is set up between earth and rover on MARS. The distance from earth to mars is approximately 55 Gm and data travels over the link at a speed of light 3 × 10⁸ m/s. calculate the minimum round trip propagation time.(6 marks) 4 (a) Compare the data rates for standard Ethernet, fast Ethernet, Gigabit Ethernet and ten Gigabit Ethernet.(4 marks) 4 (b) What is the difference between a unicast, multicast, and broad cast address? Define the type of the following destination addresses:
(i) 4A:30:10:21:10:1A
(ii) 47:20:1B:2E:08:EE
(iii) FF:FF:FF:FF:FF:FF(8 marks) 4 (c) Explain the following with respect to FAST Ethernet.
(i) Implementation
(ii) Encoding
(iii) 100 BASE-TX
(iv) 100 BASE-FX(8 marks) 5 (a) Explain the following connecting devices:
(i) Repeater
(ii) Bridge
(iii) Router
(iv) Gateway(8 marks) 5 (b) What is spanning tree? Explain with suitable example.(8 marks) 5 (c) What is VLAN? Explain.(4 marks) 6 (a) Explain the address formats for IPV4 and IPV6 address?(8 marks) 6 (b) List the classes in classful addressing and define the application of each class.(8 marks) 6 (c) What is NAT? How can NAT help in address depletion?(4 marks) 7 (a) What is the difference between a direct and an indirect delivery?(4 marks) 7 (b) List and explain three forwarding techniques.(8 marks) 7 (c) Explain dynamic routing table.(8 marks) 8 (a) Compare the TCP header and the UDP header. List the field in the TCP header that are missing from UDP header. Give the reason of their absence.(8 marks) 8 (b) What are the three domains of domains name space? Explain (8 marks) 8 (c) How does recursion resolution differ from iterative resolution?(4 marks)