Ethernet Switch - Computer Networks - Old Exam Paper, Exams of Computer Networks

Download Ethernet Switch - Computer Networks - Old Exam Paper and more Exams Computer Networks in PDF only on Docsity! Cork Institute of Technology Higher Certificate in Science in Computing – Stage 1 (NFQ – Level 6) Summer 2006 Computer Networks 1 (Time: 3 hours) Answer any 4 Questions. Examiners: Ms. M. Meagher Ms. A. Brown Mr. R. Miller Q.1 a) Draw the OSI reference model and clearly label each layer ? What are the advantages of using a layered model? At what layer of the OSI model would you associate the following? (i) IP (ii) NIC (iii) Hub (iv) UDP (v) Ethernet Switch (8 marks) b) Pick any three layers out of the OSI reference model and give a detailed description of their functions. (10 marks) c) Compare and contrast the OSI reference model with the TCP/IP reference model. (7 marks) Q.2 a) Give a detailed description of the following digital encoding techniques: • RZ Manchester (8 marks) b) Outline the characteristics of UTP cable. (5 marks) c) How does fibre-optic cable propagate light? What are the disadvantages associated with fibre-optic cable? (6 marks) d) Write a note on Terrestrial microwave transmission. (6 marks) Q.3 a) Show the structure of an Ethernet data frame, giving the size of each field. Describe the function of each field. (8 marks) b) Explain the operation of Ethernet’s link access method. (5 marks) c) Describe how a CRC is computed and used. (6 marks) d) Hubs and switches are common LAN devices. Give a brief description of each. Comment on the ability of hubs, switches to break-up collision domains. (6 marks)