Exam Questions: Internetworking & Security in Software Dev & Comp Networking, Exams of Computer Networks

Download Exam Questions: Internetworking & Security in Software Dev & Comp Networking and more Exams Computer Networks in PDF only on Docsity! Cork Institute of Technology Bachelor of Science (Honours) in Software Development and Computer Networking - Stage 3 Sping 2007 (NFQ Level 8) Internetworking and Security (Time: 3 Hours) Answer any FOUR questions All questions carry equal marks Examiners: Ms. Olivia Brickley Dr. J. Buckley Dr. A. Kinsella Q1. a. Outline the basic operation of i. Symmetric cryptographic algorithms ii. Public-key cryptographic algorithms (7 marks) b. Outline the properties of digital signatures and describe how they are implemented using public key and hashing functions. (9 marks) c. The security of a cryptosystem should rest in the key, and not in the details of the algorithm. Describe three major issues associated with Key Management. (9 marks) Q2. a.Outline the limitations of the Routing Information Protocol and detail how OSPF solves these problems. (12 marks) b. Describe the operation of the Hello protocol. What is a Designated Router and Backup Designated Router? (5 marks) c. Describe, with the aid of a diagram the DCF medium access procedure in 802.11 wireless networks. (5 marks) d. Illustrate and explain the concept of rate adaptation in wireless LANs. (3 marks) 2 Q.3 a. ATM is a cell switching technology. Explain. (3 marks) Outline the advantages of cell switching over other approaches. (2 marks) b. Identify the cell header formats for UNI and NNI giving the reasons for their differences. (4 marks) Describe how the PTI and CLP fields are used for Quality of Service (QoS) provisioning in ATM networks. (4 marks) c. What is a traffic contract? Identify the typical parameters used in such a contract. (7 marks) d. Describe how the QoS negotiated for each ATM connection is sustained in the ATM network. (5 marks) Q4. a. From the diagram below, identify and describe the five ISDN device groupings (A-E) and the interfaces (1-4) between them. (9 marks) b. Explain the difference between the BRI and PRI ISDN services. (2 marks) What is the fundamental difference between ISDN networks in the US and Europe with regard to demarcation and PRI services? (2 marks) c. Describe the two authentication procedures provided in PPP, outlining any limitations/advantages. (6 marks) d. What do you understand by the following Frame Relay terms: i. Committed information rate ii. Committed burst size iii. Excess burst size (6 marks) E CB A D Local loop Existing Terminal ISDN Terminal Terminal Adapter 2 1 4 Service provider network