IT 3202 Internet Working (New)

Transcription

1 [All Rights Reserved] SLIATE SRI LANKA INSTITUTE OF ADVANCED TECHNOLOGICAL EDUCATION (Established in the Ministry of Higher Education, vide in Act No. 29 of 1995) Instructions for Candidates: Answer any five (05) questions. Higher National Diploma in Information Technology Second Year, 1 ST Semester Examination 2013 IT 3202 Internet Working (New) Time : Three (03) hours No of pages : 05 No of questions : 08 (1) a) Describe multitier architecture? b) What are the differences between single tier and multitier architecture? (4 Marks) c) List out the 3 tiers in 3 tier architecture and explain the functionalities of each tier? d) SLIATE decided to implement an information system to automate their administrative and management task including web based student registration and online examinations. The server will be placed in the head office (Colombo) and the client machines will be placed in the head office and all ATIs in all over the Island feed the student information and to retrieve summary reports by the management officers. Students can login to the system to do their online examinations from the client machines in their ATI IT lab. Client machines may be used for teaching and learning purpose as well. The management likes to reduce the communication cost and server cost as much as possible. Two models are proposed by the top level management to fulfill the above requirements: Proposed Model A: Client Interface Application logic Network Server Database

2 Proposed Model B: Client Interface Network Server Database Application logic Choose the suitable model for the above requirement and justify your answer (7 Marks) (2). a) Give 3 advantages of layered architecture of the computer network? b) List first 3 layers in OSI reference model and state the functionalities of them? c) The TCP/IP model is given below: i. Identify the protocol which ensures the error free communication over the internet? (2 Marks) ii. Why do we need IPSEC? (4 Marks) iii. Identify one routing protocol and one routed protocol in application layer? (2 Marks) 2

3 (3). a) Define the term Network Topology? (5 Marks) b) Diagram given below is a network diagram of a 0BaseT (Fast Ethernet). Use this diagram to answer the following questions (i), (ii), (iii) and (iv) i. Identify the topology of the network diagram given above? ii. Identify the network media which can be used to connect the switch and the PC? iii. State the speed of the network? iv. Calculate the time in milliseconds to send 3000 packets from one PC to another PC within the same LAN. The packet size is 2000Bytes? (Assume other communication overheads are very small) (4). a) A Local Area Network can be segmented by some network devices. i. Give two reasons for segmenting a LAN? (4 Marks) ii. Give a network device which can be used to segment a LAN? b) What are the difference between a Switch and a Hub? (4 Marks) 3

4 c) How many collision domains are in the above network diagram? (d) Explain the term SAN? (5 Marks) (4 Marks) (5). Wireless network refers to any type of computer network that uses wireless (usually, but not always radio waves) for network connections. a) Give the advantages and disadvantages of wireless networks? (8 Marks) b) Assume that, you want to implement a wireless network for your Home to access internet from your laptop, Smart Phone and from your Smart TV. If you have an ADSL connection, what are the additional devices needed to implement your plan? (5 Marks) c) Draw a network diagram to illustrate the plan. (7 Marks) (6) (a) Give any two functions of a router? (b) Explain Static Routing and Dynamic Routing? (4 Marks) 4

5 (c) Calculate the shortest path from node A to all nodes using Dijkstra s routing algorithm for the network given below? ( Marks) F 50 B C A D 20 H E G (7) (a) What is meant by subnets? (b) Give 3 benefits of subnetting? (c) An IP address of a computer is and the subnet mask is (i) Determine the subnet ID of this computer? (ii) Find the maximum number of host within this subnet? (iii) Give the broadcast address of this subnet? (d) In a Class C IP address network, if there are 5 subnets needed how many bits (in the IP address) you will allocate for host ID? 5 (5 Marks)

6 (8) (a) Define the term Virtual LAN? (b) Give 3 advantages of VLAN? (c) Give types of VLAN? (2 Marks) (d) A leading financial company in Sri Lanka has several branches in each district. The company needs a network of branches and the head office. The data exchanged over the network is very sensitive and the company needs privacy. Assume you are the IT consultant of the above company and choose the suitable option among the following and justify your answer: Option 1 : VLAN Option 2 :PAN (Personal Area Network) Option 3 :VPN 6