Assignment on queuing and CRC

1. Data Communication assignment 2
Submission Deadline: - Nov 10 2011 MidNight.
Q1. Given the message M = 1010001101 (10 bits)
and Divisor as 110101(6 bits)
What would be the CRC?
Q2.
The data traveling speed is equal to the speed of light.
(a) Calculate the transmission delay
1. if host A sends a frame of size 500 bytes to host B.
2. if host B sends a frame of size 125 bytes to host D.
(b) Calculate the propagation delay
1. if host A sends a frame of size 500 bytes to host B.
2. if host B sends a frame of size 125 bytes to host D.
c) What would be the end-to-end delay for a frame of size 500 bytes going from host A to
host D through host B. The host B will first receive the whole frame, store it, and then
transmit it in the direction of host D.
d) Host A has a file of size 5 MB to send to host B. But, the maximum size of the file that
the host A can send at one time is 500 bytes.
1. How many frames should host A send to host B to complete the transmission?
2. How many maximum number of frames can be on the link at the maximum?
3. After how many frames, that host A has send, will host B start receiving the first
frame?
e) Host A has a file of size 5 MB to send to host D. But, the maximum size of the file that
the host A can send at one time is 500 bytes.
1. What is the total end-to-end delay?
Hint for question 2
Question 2 above is meant to revise what you have studied about Transmission delay,
propagation delay, bandwidth delay and end-to-end delay. If you can solve this exercise, it
would be easier for you to understand Flow Control algorithms that we are going to start
from next week. If you cannot answer these questions, you should see me and discuss
with me before we begin the Flow Control.
Few equations that you will need to solve the assignment are
Transmission delay (td) = size of frame / transmission speed
Propagation delay (pd)= distance/speed of light.
End-to-end delay (ed) = td + pd + qd
queuing delay is the time that a frame spend waiting for a busy host.
Queuing delay at B for a frame traveling from A to C is defined as follows.
queuing delay = (1-(BB->C/BA->B)) * tdB->C
Before using the queuing delay equation, think if the 1 st frame will wait for busy host B or
subsequent frame will wait for busy host B.