MMIS 653: Data Communication Assignment - Network Protocols Analysis

This document presents a comprehensive solution to a Data Communication assignment. It begins by addressing network delay calculations, considering factors like transmission rates and packet lengths. The solution then delves into an analysis of the HTTP protocol, examining GET/response interactions, message formats, and the retrieval of HTML files with embedded objects. The assignment also includes a Wireshark lab, where the student analyzes captured network traffic to understand HTTP requests and responses in detail. The document covers topics like transmission and propagation delays, throughput calculations, socket identification, and various aspects of HTTP headers and status codes, providing a thorough understanding of network communication principles.

Running head: DATA COMMUNICATION
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Data Communication
Name of the Student:
Name of the University:
Author Note

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DATA COMMUNICATION
Answer to question number 1
It is given that the queuing, propagation delays, and processing delays are to be ignored
and hence they are considered 0. Length = L, the transmission rates are R1, R2, R3.
Hence the total end to end delay = L (1/R1 + 1/R2 + 1/R3)
Answer to question number 2
Part a
It is given that,
Length = 1,000 bytes
Transmission Rate = 10 Mbps
Distance =1,200 km
Speed = 2.4 x 10^8 m/s
Transmission delay = (1000 bytes * 8 bytes/bit) / ( 10 Mbps * 1000000 bps/Mbps ) = 0.0008 s =
0.8 ms
Propagation delay = (1200 km * 1000 m/km) / (2.4 * 10^8 m/s) = 0.005 s = 5.0 ms
Therefore total delay = Transmission delay + Propagation delay = 5.8 ms

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DATA COMMUNICATION
Part b
The total time = (L/R) + (d/s)
Part c
Length = 1 bytes
Transmission Rate = 10 Mbps
Distance =1,200 km
Speed = 2.4 x 10^8 m/s
Transmission delay = (1 bytes * 8 bytes/bit) / ( 10 Mbps * 1000000 bps/Mbps ) = 0.0000008 s =
0.0008 ms
Propagation delay = (1200 km * 1000 m/km) / (2.4 * 10^8 m/s) = 0.005 s = 5.0 ms
Therefore total delay = Transmission delay + Propagation delay = 5.0008 ms
Part d
It takes 0.8 ms for the last bit of the packet to be put on the link.
Answer to question number 3
Part a
Given that, R1 = 500 KBs
R2=1.5Mbps, and R3=1Mbps
Therefore, R1 <R3 < R2
Therefore, the throughput is 200 Kbps.

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DATA COMMUNICATION
Part b
((50MB * 1000000B/MB)*8 B/b) / (500 kbps * 1000 bps/kbps)
= 800 seconds
Answer to question number 4
Part a
Link = 2Mbps or 2000 kbps
Bandwidth = 500 kbps
Therefore, the number of users for the network = 2000/500 = 4.
Part b
Probability that a giving user is transmitting = 0.1
Part c
Probability for single user = 0.1
Therefore, the probability for 5 users = (1/10) ^ 5 = 0.00001
Answer to question number 5
The port number of the socket in the destination process and the IP address of the
destination host are used by a process running on one host to identify a process running.
Answer to question number 6
Part a
False. Different objects have their own request message and response message.

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DATA COMMUNICATION
Part b
True.
Part c
True.
Part d
False, it is request generation time.
Answer to question number 7
Application layer: The data is passed onto the transport layer.
Transport Layer: Encapsulates the application layer messages.
Network layer: encapsulates transport layer message with a header.
Link layer: encapsulates network layer message with a header.
Wireshark Lab: HTTP
Frame 215: 431 bytes on wire (3448 bits), 431 bytes captured (3448 bits) on interface 0
Ethernet II, Src: HonHaiPr_18:d7:ed (54:35:30:18:d7:ed), Dst: 0c:9d:92:91:2c:9c
(0c:9d:92:91:2c:9c)
Internet Protocol Version 4, Src: 192.168.43.246, Dst: 128.119.245.12
Transmission Control Protocol, Src Port: 56622, Dst Port: 80, Seq: 1, Ack: 1, Len: 377
Hypertext Transfer Protocol
GET /wireshark-labs/HTTP-wireshark-file1.html HTTP/1.1\r\n

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DATA COMMUNICATION
[Expert Info (Chat/Sequence): GET /wireshark-labs/HTTP-wireshark-file1.html HTTP/1.1\
r\n]
Request Method: GET
Request URI: /wireshark-labs/HTTP-wireshark-file1.html
Request Version: HTTP/1.1
Host: gaia.cs.umass.edu\r\n
User-Agent: Mozilla/5.0 (Windows NT 6.2; Win64; x64; rv:72.0) Gecko/20100101
Firefox/72.0\r\n
Accept: text/html,application/xhtml+xml,application/xml;q=0.9,image/webp,*/*;q=0.8\r\n
Accept-Language: en-US,en;q=0.5\r\n
Accept-Encoding: gzip, deflate\r\n
Connection: keep-alive\r\n
Upgrade-Insecure-Requests: 1\r\n
\r\n
[Full request URI: http://gaia.cs.umass.edu/wireshark-labs/HTTP-wireshark-file1.html]
[HTTP request 1/2]
[Response in frame: 223]
[Next request in frame: 225]

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DATA COMMUNICATION
Answer to question number 1
Browser Version: 1.1
Server Version 1.1
Get Print:
Request Version: HTTP/1.1
Response Print:
Response Version: HTTP/1.1
Answer to question number 2
Get Print:
Accept-Language: en-US,en;q=0.5\r\n

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DATA COMMUNICATION
Answer to question number 3
The address of my computer is 192.68.43.246
gaia.cs.umass.edu server = 128.119.245.12
Get Print:
Internet Protocol Version 4, Src: 192.68.43.246, Dst: 128.119.245.12
Response Print:
Internet Protocol Version 4, Src: 128.119.245.12, Dst: 192.68.43.246
Answer to question number 4
Status code is 200
Response Print:
Status Code: 200
[Status Code Description: OK]
Answer to question number 5
Response Print:
Last-Modified: Mon, 17 Feb 2020 06:59:02 GMT\r\n
Answer to question number 6
128 bytes content are being returned.
Response Print:
Accept-Ranges: bytes\r\n

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DATA COMMUNICATION
Content-Length: 128\r\n
Answer to question number 7
No, there are no headers which are not being displayed.
Answer to question number 8
No there is no “IF-MODIFIED-SINCE” line in the HTTP GET

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DATA COMMUNICATION
Answer to question number 9
Yes the content was returned explicitly by the server.
Answer to question number 10
No there is no “IF-MODIFIED-SINCE” line in the HTTP GET

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DATA COMMUNICATION
Answer to question number 11
404 not found.
Answer to question number 12
My browser only sent 1 request message
Packet number 53 contains the GET message for the Bill or Rights
Answer to question number 13
Packet number was 60 for the response.
Answer to question number 14
Status code was 200 and phrase was OK.

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DATA COMMUNICATION
Answer to question number 15
4 TCP segments were needed to carry the single HTTP response and the text of the Bill
of Rights.

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DATA COMMUNICATION
Bibliography
Avena-Koenigsberger, A., Misic, B., & Sporns, O. (2018). Communication dynamics in complex
brain networks. Nature Reviews Neuroscience, 19(1), 17.
Wollschlaeger, M., Sauter, T., & Jasperneite, J. (2017). The future of industrial communication:
Automation networks in the era of the internet of things and industry 4.0. IEEE industrial
electronics magazine, 11(1), 17-27.