SIT202 Computer Networks: Cookie & TCP Connection - Problem Report

This report provides a detailed explanation of the cookie mechanism in online shopping, elucidating the six steps involved in the interaction between a client and a server, including the generation of cookies, identification, and exchange of information. It further discusses TCP connection establishment and disconnection, detailing the three-way and four-way handshakes, respectively. The report also addresses scenarios such as half-open connections and simultaneous FIN exchanges, referencing relevant literature and resources.

Problem Resolving Report 1
Problem Solving Report
by (Name)
Class Name
Tutor
University Name
Date of Submission

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Question 1.A
In the figure below, it can be perceived that it is a diagram showing a communication
amongst client and server computing systems. A cookie is deposited on a server computer
and generates a session on the client computer side. The following are the associated steps:
Step 1
In the opening step, client workstation enquiries besttoys.com webpage for it to build
a link for extended communication. In a comeback, the web server produces a cookie file on
webserver offering it with exclusive ID, for example in our case study, the exclusive ID
number is ID 12343.
Step 2
In the next step, cookie is generated with an exclusive identifier. The identifier in this
case is 12343. Server computer will answer to the client computer on the grounds of the
produced ID with client computer query.
Step 3
In this step three, the client computer will produce a cookie. The cookie produced by
the client computer has same identifier as the computer server. Let's say, the client computer
will produce a cookie on its end for the reason of forthcoming communication. In case there
are forthcoming communications, identifier 12343, will be in deployment.
Step 4
In the next step, the client will obtain a response from the server. The response
encompasses the demanded price by client computer in step 3 above. Moreover, the reply
also comprises the update cookie in cooperation with the last enquiry demanded by client.
Step 5
In step 5, the disbursement has to be done by client and send to the server in addition
to data information regarding payment amount as well as product data with client cookie
identifier. Disbursement amount possibly will include information such as amount, currency,
modes of payment and so forth. Whereas product information may comprise of quantity
requested and product availability.
Step 6
This is the last step. In the final step six, the server computer sends to the client a final
verification. The verification regards client’s receipt of payment of product order that was
requested. The cookie identifier is updated on server (Experts, 2017 ).

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Question 1.B
Diagram
In the above drawing, I have pictured the same case study as in 1A using Microsoft
Visio modelling tool. From the picture, Deakin University is the chief intermediary between
the publicity company and the webpage that manages visitor cookie. The website after it
produces the cookie, the generated cookie’s copy then is forwarded to the manufacturing
company. The cookie copy forwarded to the manufacturer enterprise contains visitor’s
information who logs on the Deakin University website and activates the links available
(Shetty, et al., 2015 ).
Question 2
TCP Connection Establishment
Establishment of connection
For a connection to be established, the TCP employs use of 3-way handshake, prior the
client tries to establish a connection with computer server side, computer server has to bind
and assure to listen to a port not exposed for it interlink. This is called inactive open
communication. Subsequently the inactive open has been generated, the client computer
might recruit active open.to have an establishment, the 3-path handshake takes place as
outlined below:
1. SYN: the contributing open is performed by client releasing a SYN to server. A client
computer produces the same seven times.
2. A SYN-ACK: in comeback with SYN-ACK. The ACK identifier is generated (like,
A+1), the server computer selects alternative unique sequence number let’s say B.
3. ACK: lastly, the client workstation succeeds an acknowledgement from the server
computer. Classification identifier is set to receive ACK value (i.e. X+1). The ACK
figure is raised by 1 more than the acknowledged sequence ID.
At this instant, both the client computer and the server computer have received an ACK of
interlinking. Steps one and two establishes a connection constraint for unidirectional and the
acknowledgement. Final two steps initiate connection factor (i.e. known as identifier) for

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opposite direction and it’s ascended to. Once the full-duplex events have been established.
The communication is initiated (Vacca, 2012).
Disconnecting a connection
The connection end procedure uses a 4 way handshake. It is good to mention that each side of
connection terminates individually. Just in case any of the endpoint computing device wishes
to bring to an end half of its connection, it sends an acknowledgement and FIN packet to the
opposite partner end device. The other end recognizes with ACK. hence, a conventional
closure necessitates the pair of ACK and FIN sections from each TCP finale part. As soon as
both ACK/FIN connections have been determined, the other end that released FIN before
receipting one has to time lag for timeout in advance the connection is closed. During the
course of this period, the innate port is not obtainable for fresh links. This inhibits
misunderstanding since overdue packets are delivered in sequential connections.
A linkage might be half-open that is to say, one end side has ended its connection end but
opposite has not dismissed. The part that has terminated the linking cannot send any form of
data in the established link. Nevertheless, the opposite side can send info to the opposite side.
The dismissed side has to persist assessing the info till the opposite end terminates too.
Furthermore, it is possible to cut the link by a 3-way handshake, that is, when workstation 1
sends a FIN and workstation 2 retorts with a FIN and a nod and workstation 1 replies back
with a nod too.
On the other hand, it may occur in coincidence that workstation A and workstation B send
out a FIN concurrently, both opposite ends have an ACK. Such a case is taken as a 2-way
handshake. This implies, FIN sequence has been achieved in parallel form for both endpoints.
It is good to mention that some workstation TCP stacks do practice half-duplex adjacent
series. Such applications include and are not limited to Linux and HP-UX. In such scenarios,
the involved workstations close connection actively minus reading inward info, the
workstations have a RST instead of deployment of FIN. This guarantees the TCP application
that the distant computing device has finished all data the previous device sent. The resident
computing device waits for FIN from the distant computing device. As the distant computer
cannot distinguish between information Loss RST and a linking aborting RST, both throw
away all information that was received (Odom, 2013).

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References
Experts, D., 2017 . Computer Knowledge for SBI/ IBPS Clerk/ PO/ RRB/ RBI/ SSC/ Railway. 2nd ed.
New Delhi: Disha Publications .
Odom, W., 2013. CCENT/CCNA ICND1 100-101 Official Cert Guide. Indianapolis: Cisco Press.
Shetty, N. R., Prasad, . & Nalini, ., 2015 . Emerging Research in Computing, Information,
Communication. 1 ed. Salmon Tower Building New York City: Springer.
Vacca, J. R., 2012. Computer and Information Security Handbook. London : Newnes.