Question 1 (4 marks)
With respect to TCP/IP; a) Describe what physical, logical and port addresses are and why they are required. b) Provide a real example of a physical, logical and port address - this should be from your own computer on your own network, or a lab computer or a work computer – include details of how you obtained each of the addresses – for the port address identify the application or program that is using it.
Your Answer: a) Physical address can be use to the local network as link address.
Logical address is a 32-bit address in internet and it is necessary for universal communications, A universal addressing system in which each host can be identified uniquely, regardless of the underlying physical network.
Port address is 16 bits length in TCP/IP and it is the label assigned to a process in TCP/IP architecture.

b) Like my computer. I type CMD and ipconfig /all in my computer and I find my Physical address is 00-26-C6-38-EB-AC and My ip is 192.168.1.3

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Question 2 (4 marks)
Describe in detail both CSMA/CD and CSMA/CA. Ensure you include answers to the following questions: * What is CSMA/CD? * What is CSMA/CD used for? * Why is CSMA/CD required? * Why is CSMA/CA used for wireless LAN’s rather than CSMA/CD?
Your Answer:
• What is CSMA/CD?
CSMA/CD is Carrier-Sense Multiple-Access with Collision Detection
• What is CSMA/CD used for
CSMA/CD is used for controlling access to the network media and used to detect collisions on the network which happen when two stations attempt to transmit at the same time.
• Why is CSMA/CD required?
Because If two stations attempt to transmit at the same time, all stations detect it. Both stations that were involved in the collision choose a random time interval to wait before attempting to transmit their messages again. If a collision happens again, the time intervals are increased.
• Why is CSMA/CA used for wireless LAN’s rather than CSMA/CD?
Because CSMA/CD must be able to send data and receive collision signals at same time which mean increased bandwidth and cost a lot. A collision can occur with CSMA/CD . Marks Awarded:
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Question 3 (6 marks) a) Change the following IP addresses from dotted-decimal notation to binary notation:
192.27.44.137
128.11.53.127 b) Change the following IP addresses from dotted-decimal notation to hexadecimal notation:
122.25.53.127
194.96.82.121 c) Change the following IP addresses from hexadecimal notation to dotted-decimal notation:
0xD1A86F47
0x51EF3CB6 d) Change the following IP addresses from binary notation to dotted-decimal notation:
01101010 01001101 01110101 10111011
10000001 00101011 10011011 01101011 e) Find the class of the following IP addresses:
122.23.13.62
199.126.6.21 f) Find the netid and hostid of the following classful IP addresses:
125.145.31.127
141.34.37.120
Your Answer: