Unlock document.
This document is partially blurred.
Unlock all pages and 1 million more documents.
Get Access
a) There are
Q
nodes (the source host and the
1Q
routers). Let
q
proc
d
denote the
processing delay at the
q
th node. Let
q
R
be the transmission rate of the
q
th link and
let
Problem 18
On linux you can use the command
traceroute www.targethost.com
Traceroutes between San Diego Super Computer Center and www.poly.edu
a) The average (mean) of the round-trip delays at each of the three hours is 71.18 ms,
b) In this example, the traceroutes have 12 routers in the path at each of the three hours.
d) The average round-trip delays at each of the three hours are 87.09 ms, 86.35 ms and
86.48 ms, respectively. The standard deviations are 0.53 ms, 0.18 ms, 0.23 ms,
respectively. In this example, there are 11 routers in the path at each of the three
Problem 19
An example solution:
Traceroutes from two different cities in France to New York City in United States
Problem 20
Throughput = min{Rs, Rc, R/M}
Problem 21
If only use one path, the max throughput is given by:
Problem 22
Probability of successfully receiving a packet is: ps= (1-p)N.
Problem 23
Let’s call the first packet A and call the second packet B.
b) If the second link is the bottleneck link and both packets are sent back to back, it must
be true that the second packet arrives at the input queue of the second link before the
second link finishes the transmission of the first packet. That is,
If we send the second packet T seconds later, we will ensure that there is no queuing
delay for the second packet at the second link if we have:
Problem 24
Problem 25
a) 160,000 bits
Problem 27
a) 80,000,000 bits
Problem 28
a) ttrans + tprop = 400 msec + 80 msec = 480 msec.
Problem 29
Recall geostationary satellite is 36,000 kilometers away from earth surface.
Problem 30
Let’s suppose the passenger and his/her bags correspond to the data unit arriving to the
top of the protocol stack. When the passenger checks in, his/her bags are checked, and a
Problem 31
a) Time to send message from source host to first packet switch =
sec4sec
108
6
u
c) Time at which 1st packet is received at the destination host =
sec153sec5mhopsm u
. After this, every 5msec one packet will be received; thus
time at which last (800th) packet is received =
sec01.4sec5*799sec15 mm
. It
can be seen that delay in using message segmentation is significantly less (almost
1/3rd).
Problem 32
Problem 33
There are F/S packets. Each packet is S=80 bits. Time at which the last packet is received
dS
Problem 34
The circuit-switched telephone networks and the Internet are connected together at
