Data Communication and Net-Centric Computing (COSC1111/2061) Assignment 2 (S2 2019)
Aim: Explore Internet based communication technologies.
Instruction This assignment includes Tasks 1, 2 and 3 (optional with bonus)
• Tasks 1 and 2 contribute to 30% of the total mark.
• Due date: 7th October 2019.
• This is a group-based assignment with maximum 3 members in each group.
• This assignment requires demo on week 12. No demo no marks.
Late submission policy
• There will be a late submission period of 5 working days for this assignment.
• Late submissions will incur a penalty of 10% per working day, unless prior arrangement has been
made regarding an extension.
• Submissions received after the late submission period expires will not be assessed.
Task 1 (25 marks)
1.1
1.2
1.3
1.4
1.5
Investigation on the process of end-to-end communication referenced to Figure 1. Using TCP/IP suite, take sending email from Host A port 10 to Host B port 20 as an example, to show how the message is packetized and encapsulated down to the physical layer. (6 marks)
Fill in the box 1-4 in Figure 1(b) with appropriate number. Discuss in details on the functions of transport layer and network layer. How these two layers complement each other. (5 marks)
Investigation on the message destination Host B. When the decapsulation process applies? How the decapsulation works on the corresponding layers? (4 marks)
Investigation on how the reliable end-to-end communication is achieved. Draw a picture to discuss how a three-way handshake is achieved. (4 marks)
Discuss how router 1 accepts incoming packets, processes those packets and moves them to the next hop. (4 marks)
1.6 There are physical address and logic address associated with the communication. Discuss what
address changes and what address does not change in above case. (2 marks)
Task 2 (5 marks) There is an IPv4 address 150.112.15.138. The subnet mask is 255.255.255.128. 2.1 What is the subnet address? (2 marks)
2.2 What is the range of possible IP addresses? (2 marks)
2.3 Determine the number of usable (not already reserved) addresses for hosts. (1 mark)
Task 3 (optional with 5 marks bonus) Implement part of the function you discussed above.
Note:
1. You need to write all group member information on the first page of your submission.
2. Your answers start from specific message, e.g., Alice is sending “ABCD …” through an IP address,
such as “150.112.15.38”. Then how the “ABCD …” is processed, etc.
Bonus part due 14th October. What to submit for the bonus part:
• Detailed instruction on how to execute the program with screenshots.
• Submit all files in a zipped version and a README.md document with setup instructions you used.

(a) Three LANs are connected by two routers. Sender Host A uses port 10. Receiver Host B uses port 20.
(b) End-to-end data communication.
Figure 1 Each device (computer or router) has a pair of addresses (logical and physical) for each connection.