IEG3310hw1 with solution

IEG3310hw1 with solution - IEG 3310, 2nd semester 2009...

Info iconThis preview shows pages 1–2. Sign up to view the full content.

View Full Document Right Arrow Icon
IEG 3310, 2 nd semester 2009 Homework 1 Due on Noon, 23 rd Feb (Monday), 2009 Every Student MUST include the following statement, together with his/her signature in the submitted homework. “I understand the University guidelines on academic honesty as shown in the web page http://www.cuhk.edu.hk/policy/academichonesty/ and I agree to comply with the guidelines. I declare that I do not plagiarize or cheat in any way that violates the spirit of the guidelines. I understand the severity of disciplinary action should the guidelines be violated. Signed (Student _____________________) Date: _____________________ 1. (Queuing delay) suppose N packets arrive simultaneously to a link at which no packets are currently being transmitted or queued. Each packet is of length L and the link has transmission rate R. what is the average queuing delay for the N packets? If 1 packet arrives at the router every L/R seconds, what is the average arrive rate? Suppose N packets arrives at the router every NL/R seconds, what is the average arrive rate? What can you tell from this question? Answer: Total delay = 0 + L/R + 2*L/R +… + (N-1)*L/R = N*(N-1)*L/R Average delay = (N*(N-1)*L/R)/N = (N-1)*L/R The 1 st case: Average arriving rate = 1/ (L/R) = R/L packets/sec = R bits/sec The 2 nd case: average arriving rate = N/ (NL/R) = R/L packets/sec = R bits/sec The traffic nature can affect the queuing delay. 2. (Message segmentation) in a packet-switched network, data are transported as packets from source to destination. In the following, you can choose to explain your answer either using mathematical equations or without using mathematical equations. The key is that your explanation must indicate that you understand the issues. (a) Name and explain one advantage of transporting a large file using large packets. (b) Name and explain two advantages of transporting a large file using small packets. Answer: Advantages of transporting a large file: Using large packets can reduce the overhead appending on each packet and reduce the computation cost from the packet ordering Advantages of transporting a large file using small packets:
Background image of page 1

Info iconThis preview has intentionally blurred sections. Sign up to view the full version.

View Full DocumentRight Arrow Icon
Image of page 2
This is the end of the preview. Sign up to access the rest of the document.

Page1 / 5

IEG3310hw1 with solution - IEG 3310, 2nd semester 2009...

This preview shows document pages 1 - 2. Sign up to view the full document.

View Full Document Right Arrow Icon
Ask a homework question - tutors are online