Data Communication and Networking

Question 1 (a) Compare the difference of functionality of layers in OSI model vs TCP/IP model. (b) Demonstrate any TWO (2) TCP/IP protocols using an Open Source Wireshark software. Explain how each protocol works and provides guaranty of packet delivery to the host. Provide your Wireshark screenshot as evidence.

Question 2 Checksum is an error detection method that is used in the Internet that computes a numerical value according to the number of set or unset bits in a message and sends it along with each message frame. The same checksum function is applied to the message frame to retrieve the numerical value at the receiver end. A message of 1001, 1100, 1010 and 0011 is transmitted using the Internet checksum (4-bit words). (a) Calculate the value of checksum. Write the steps to find the checksum at the sender site. (b) Assuming no error occurs during transmission, determine either the data received or not. Write the steps to find the checksum at the receiver site. (c) Assuming the message is transmitted using the Internet checksum (16-bit words) and the header has the following data: 1000 0110 0101 1010 1010 1100 0110 0000 0111 0001 0010 1010 1000 0001 1011 0101 Find the value of checksum.