Assignment: Assignment 3 - Transport Layer: Reliable Data Transfer and UDP

Posted: 17 September 2019

Deadline: 2019-09-28 16:00

This assignment contains 2 questions that should be possible to answer with the material from the classes in the 3rd. week, and a wireshark exercise on UDP.

The answers must be submitted in the E-test section in Blackboard before deadline.

Pipelining Protocols for RDT

  1. Go Back N: You have 6 packages to send, and a window size of 3. Draw a diagram of how the Go Back N protocol will handle this when the ack for packet number 2 gets lost the first time it is sent, and packet number 4 gets lost the first time it is sent.

  2. Selective Repeat: You have 6 packages to send, and a window size of 3. Draw a diagram of how the Selective Repeat protocol will handle this when the ack for packet number 2 gets lost the first time it is sent, and packet number 4 gets lost the first time it is sent.

Wireshark: UDP

You can find the wireshark UDP exercise in the Instructions menu → Wireshark UDP. Work your way through it, and submit the relevant answers in the test in Blackboard (questions are below too).

  1. Upload a screenshot of the wireshark packet, with the UDP info folded out.

  2. Determine how many fields there are in the UDP header. Name these fields.

  3. Determine the length (in bytes) of each of the UDP header fields.

  4. The value in the Length field is the length of what? Verify your claim with your captured UDP packet, and document how you reached your conclusion from the packet studied.

  5. What is the maximum number of bytes that can be included in a UDP payload?

  6. What is the largest possible source port number?