1. Due: a start of class Oct 12
Networks Midterm 1
Due: a start of class Oct 12
Name ______________________________

2. Instructions
You are asked to gather data using wireshark and answer the following questions. I expect well documented and well written answers including sample output.
Actions
Start Wireshark and start a capture session
Open the web page
End the capture session

3. Question 1
Examine the trace and find the exchange of packets between your machine and the
web server (the host providing the web pages to your machine). Can you find an
example packet in this exchange where the packet contains details about the type of
your web browser (e.g., if it is Fire Fox, Internet Explorer, etc.) being used? If you can
find this then what is the value of this attribute in your particular trace?
Why is this information given?
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4. Question 2
In the trace you can see many protocols listed! Some of these protocols are called
transport protocols. Which transport protocol is used between your machine and the
web server?
Why would you think this one is used instead of an alternative?
You will see that other protocols are captured in your trace. One such protocol is
HTTP. What is the relationship between the transport protocol you identified and
HTTP?
Both protocols are used to satisfy your browser's request for a web page.
Why was more than one protocol used?
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5. Question 3
In the trace you will find IP addresses within the packets. Find an example packet in
the trace where the IP address associated with your machine is present. Provide this
example packet with your answer. Why is the IP address present in the particular
packet you selected (what purpose does it serve)?
How are IP addresses and port numbers used, to address what specifically?
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6. Question 4
We discussed protocol layers in class. Which layer is the IP associated with and why
isn’t it associated with say the application layer?
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7. Question 5
Each node has a unique Link Layer MAC address. Can you find the MAC address
for your machine within this trace. What is the MAC address of your machine?
Provide a trace of the packet in which you found it.
Why do you think a MAC address is needed given that your machine has an
IP address?
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8. Question 6
Consider the short trace you just captured. You will see many different protocols
listed in the trace. Excluding the HTTP and TCP protocols identify one of these other
protocols. Describe why this protocol is being used and what it is all about (Google it
and summarize the service it offers.
Recall a protocol is the core of a layer that provides a service to a higher layer – what
is this service for one of the protocols in your list other than the obvious ones
DNS, TCP, HTTP).
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9. Question 7
You have trained your dog to carry 10 DVDs to a specified destination. Each
DVD contains 4 gigabytes of information. Suppose that your dog travels at 10
Km/hr. For what range of distances does your dog have a higher data rate than a
155 Mbps transmission line?
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10. Question 8
Why is UDP used instead of TCP in applications such as video streaming?
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11. Question 9
Sketch the encoded bit stream for using Manchester encoding.
Why is Manchester encoding used?
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