COMP2410/COMP6340_Semester 1 Networked Information Systems Semester 1 - End of Semester, 2017

PART A. Both COMP2410 and COMP6340 students

Question 1.

Describe the Internet Layers model as a table with the following three columns: 1) the layer’s name, 2) its purpose, and 3) a common standard/protocol relevant to this layer. Remember to have a row for each layer.

0-20 points, format your full answer as a max 0.5-page table

Question 2.

In the context of Virtual Local Area Network (VLAN) messaging, walk us through the four cases of 1) Same Subnet Same Switch, 2) Same Subnet Different Switch, 3) Different     Subnet Same Switch, and 4) Different Subnet Different Switch. Please include a figure of your example network and specify the sender(s) and receiver(s) of the message.             Remember to provide for each case a flow chart that explain in a concrete way what is    happening to the message as it travels through your example network in each case.

0-20 points, format your full answer as a max 0.25-page figure and four flow charts (max 0.25 pp. each)

Question 3.

Consider the Textbook Management Focus 9-4 below. What other alternatives do you    think Cisco considered for their wide area networks (WANs)? Why do you think they did what they did? Please define and relate the ten underlined concepts in your answer, but remember that these are not the only aspects to cover in your answer.

For years, Cisco Systems Inc. had supported its Europe/Middle East/Africa (EMEA) offices with a series of star networks connected to stars (called a hub-and-spoke     design). The WAN core was three offices (London, Amsterdam, and Brussels)         connected to each other in a full mesh using OC-3 circuits. Each of these three       offices was the center of a star network that connected to three other secondary     star networks and 10 major sites (9 stars and 30 major sites in total). The nine        secondary stars connected a total of 85 other offices. The network was at capacity, and any time one of the three core offices (or one of the hubs of the secondary       stars) needed to be taken down for maintenance, it shut down a major part of the    network. Worse still, it looked like the London office would need to move to a new   building, which meant significant rewiring of the network. Cisco chose to implement a full mesh [Multiprotocol Label Switching] MPLS network to provide greater            capacity and better flexibility. Each office is connected into the MPLS carrier’s         cloud with two separate MPLS circuits that are laid in physically separate routes to  provide better reliability in case a circuit is accidentally cut. Each of the two circuits is sized for the needs of the specific office, ranging from 64 Kbps up to 45Mbps.      Since the three core offices no longer route traffic for the entire network, they don’t  need as much network capacity as they did with the hub and spoke design. The      new network has significantly increased capacity, reliability, and flexibility, while       keeping costs about the same.

0-20 points, format your full answer as a max 500-word essay

PART B. Both COMP2410 and COMP6340 students

Question 4. Choose 1 out of the 2 options below.

Option 1. Compare and contrast a thick-client architecture and thin-client architecture in the context of client-server architectures and functions of the application layer.                Remember to name and explain the functions as well as relate them with both the thick- client and thin-client architecture.

0-20 points, format your full answer as a max 250-word essay

Option 2. First, describe the traditional method and building-block method for network design and then explain how you could apply the latter method to the following case:

Shangri-La’s Rasa Sayang Resort and Spa is a five-star luxury resort hotel located on the scenic Batu Feringgi Beach in Penang, Malaysia. The resort has two main    buildings, the 189-room Garden Wing and the 115-room Rasa Wing, with an           additional 11 private spa villas. Over the years, the resort had installed three           separate networks: one for the resort’s operations, one for its Point-of-Sales (POS) system, and one for Internet access for guests (which was wired, not wireless). The networks were separate to ensure security, so that users of one net- work could not gain access to another. As part of a multi-million-dollar renovation, the resort           decided to upgrade its network to gigabit speeds and to offer wireless Internet         access to its guests. Rather than build three separate networks again, it decided to build one network using VLANs. The resort installed 12 wireless access points and 24 VLAN switches, plus two larger core VLAN switches. The VLAN architecture      provides seamless management of the wired and wireless components as one        integrated network and ensures robust performance and security.

0-20 points, format your full answer as a max 250-word essay

PART C. COMP2410 students only

Question 5. Choose 1 out of the 2 options below.

Option 1. Let us consider an example, where a client in the Building A sends an email to another client in the Building B through a router in Building A and another router in            Building B. Explain how the protocol data units flow through the layers of the Internet        model. You can assume that the addresses are known and correct. After this, explain       how Virtual Local Area Networks (VLANs) could be useful in this example and what          VLAN transparency means in this context.

0-20 points, format your full answer as a max 250-word essay

Option 2. Compare and contrast symmetric encryption and asymmetric encryption in the context of an accountant wishing to email his/her customers’ tax documents as an attachment (ZIP file of text documents and spreadsheets) securely to his/her line        manager and the manager then decrypting the attached document.

0-20 points, format your full answer as a max 250-word essay

PART D. COMP6340 students only

Question 5. Choose 1 out of the 2 options below.

Option 1. Let us consider an example, where a client in the Building A sends an email to another client in the Building B through a router in Building A and another router in            Building B. Explain how the protocol data units flow through the layers of the Internet        model. You can first assume that the addresses are known and correct. After this, relax    these assumptions and explain how subnetting, broadcasting, and introducing Virtual       Local Area Network (VLAN) switches applies to this example, using a figure to support     your narrative text. Finally, explain the concept of VLAN transparency in this context.

0-20 points, format your full answer as a max 500-word essay, supported by one figure

Option 2. Compare and contrast symmetric encryption and asymmetric encryption in    the context of an accountant wishing to email his/her customers’ tax documents as an    attachment (ZIP file of text documents and spreadsheets) securely to his/her line            manager and the manager then decrypting the attached document. Please include in     your answer a figure that explains the symmetric encryption-decryption process and       another figure that explains the asymmetric encryption-decryption process in the context of the accountant and manager’s communication.

0-20 points, format your full answer as a max 250-word essay and two figures