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Main points of this past exam are: Perceived Problem, Physical Layer Technology, Dsl Network, Network Devices, Physical Channel, Message Exchange, Data-Link Layer, Address, End-Application, Symmetric Cryptographic Algorithm
Typology: Exams
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(NFQ Level 8)
Answer any FOUR questions. All questions carry equal marks.
Examiners: Dr. J. Buckley Dr. A. Kinsella Mr. A. McDonald
Q1. a. Outline the operation of NAT in a security device. What perceived problem in the Internet was NAT originally devised to solve? (6 marks) b. What does DHCP do? Why is it better than BOOTP? Outline how DHCP operates? Why is DHCP Relay necessary? (8 marks) c. DSL is a physical layer technology. Explain. (4 marks) d. Illustrate the structure of a DSL network, explaining the functions of the three network devices found in such a network. (^) (7 marks)
Q2. a. There are two access methods available to an ISDN networks, what are they? Outline the differences? (4 marks) b. ISDN offers logical channels using TDM on a physical channel, explain? (7 marks) c. ISDN uses Q.931 signalling. Outline a basic Q.931 message exchange for a successful call- setup. (10 marks) d. At the data-link layer, ISDN uses two values to address the end-application on a remote terminal, what are they? (4 marks)
Q3 a. In the diagram below, name the five ATM interfaces. Outline the structure of the ATM cells used at interface 1 and interface 2, explaining the use of each of the fields in the cells.
(10 marks) b. What is Connection Admission Control in an ATM network? (4 marks) c. In cryptography, outline the basic protocol of: i. A Symmetric cryptographic algorithm; ii. A Public-key cryptographic algorithm; iii. Digital signature algorithm with public keys. (11 marks)
Q4. a. Describe the basic functionality of a proxy-firewall? (5 marks)
b. What is a VPN and outline three basic types of VPN? (5 marks) c. What is IPSec? What is a VPN and outline three basic types of VPN? (^) (4 marks) d. What are the four main characteristics of IPSec Encapsulating Security Payload? (3 marks) e. In IPSec, what is a security association? (4 marks) f. ISAKMP is a protocol used in IPSec, for what? (4 marks)
With AIP
PublicATM Switch
Public Carrier
Public ATMSwitch
With ATM NIC