Assignment
1. Many more square-wave digital encoding schemes exist than NRZ-L, NRZI, Manchester, differential Manchester, and bipolar-AMI. List three other encoding techniques and show an example of how each encodes.
2. You have been asked to recommend a type of wiring for a manufacturing building. The size of the building is 200 meters by 600 meters (corresponding to about 650 feet by 2000 feet), and it houses large, heavy machinery. Approximately 50 devices in this building must be connected to a computer system. Each device transmits data at 2 Mbps and sends a small packet of data every two to three seconds. Due to various building-related factors, any cable used for this network has to be suspended high overhead in a hard-to-reach location. What type of cable would you recommend? Use the media selection criteria introduced in the Textbook to elucidate your answer.
3. Consider a VGA screen that has 640 x 800 pixels per screen. Further assume that each pixel is 24 bits (8 for red, 8 for blue, and 8 for green). If a movie video presents 30 frames (images) per second, how many bytes will a two-hour movie require for storage? How many bytes can a standard DVD hold? What then must be the compression ratio?
4. In a sliding window error control system, Station A sends three packets with bytes 0-100, 101- 200, and 201-300, respectively. The second packet with bytes 101-200 is held up somewhere in the network long enough that the third packet arrives before the second one. Create a diagram of this error control scenario and show the response(s) that Station B will send. Now assume that five seconds after Station B responds, the second packet shows up. What does Station B do now?
5. A transparent switch is inserted between two local area networks ABC and XYZ. Network ABC has workstations 1, 2 and 3, and network XYZ has workstations 4, 5, and 6. Show the contents of the two forwarding tables in the switch as the following packets are transmitted. Both forwarding tables start off empty.
• Workstation 2 sends a packet to workstation 3.
• Workstation 2 sends a packet to workstation 5.
• Workstation 1 sends a packet to workstation 2.
• Workstation 2 sends a packet to workstation 3.
• Workstation 2 sends a packet to workstation 6.
• Workstation 6 sends a packet to workstation 3.
• Workstation 5 sends a packet to workstation 4.
• Workstation 2 sends a packet to workstation 1.
• Workstation 1 sends a packet to workstation 3.
• Workstation 1 sends a packet to workstation 5.
• Workstation 5 sends a packet to workstation 4.
• Workstation 4 sends a packet to workstation 5.
6. Using the procedure for Dijkstra's algorithm and a weighted network graph shown below, find the least-cost route from Node A to all other nodes.
7. What are the advantages and disadvantages of using dynamic IP address assignments?