CS 125, Fall 2017
Homework 1—Network Parameters
Due: Monday, September 11, 2017
The purpose of your assignment is to help you understand some of the
mathematical and numerical relationships between various network
parameters. All of the problems are taken from the class textbook.
Please submit your answers on paper (preferably typed and formatted
with LaTeX). The due date is the beginning of class on Monday,
September 11, 2017.
In Chapter 1 of the book, do problems P6, P12, P14, P15, P16, P22
(first part), P24, P25, and P33. At the bottom of your submission,
also estimate the amount of time you spent on this assignment.
- a is the rate of packets arriving at the link,
in packets/second, as defined in P15.
- Calculate the probability of successful reception. You
are welcome to also find an expression for the number of
retransmissions; if you do so, it is useful to recognize
that a geometric random variable is involved.
- An American football field is 100 yards long (actually
120 yards because of the two 10-yard end zones). A yard
is about 0.91 meters. So a football field is 91 meters,
or about 110 meters including the end zones.
- You'll have to draw on your maxima/minima skills from
calculus to solve this one. Think about how long it takes
before the first bit of the last packet can be
transmitted, and thus how long it takes the last packet to
arrive at the destination through the two routers. Find
an expression for the total time to get the whole file to
its destination and then minimize that with respect to
© 2017, Geoff Kuenning
This page is maintained by Geoff