Using Cookies In Online Shopping And TCP Segments In Client-Server Connection, Essay.

Explanation of Six Steps of Cookie Use in Online Shopping

Question: 1
1. A) The World Wide Web was originally designed as a stateless entity. However, over time it was identified that a stateful relationship between a web client and a web server can benefit in many ways including e-commerce, collecting web behaviour of web users etc. The cookie mechanism was introduced for this purpose. In your lecture slides (week-8 to week-9), the following diagram demonstrates the use of a cookie. Explain each of the six steps indicated in the following diagram for using the cookie in online shopping.
Marking Guideline:
Explained clearly all six steps (server/client activity, cookie, contents in the request/response)
Explained but missing two components or have two errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 4 components or have 4 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 6 components or have 6 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 8 components or have 8 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 10 components or have 10 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 12 components or have 12 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 14 components or have 14 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 16 components or have 16 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response)
Explained but missing 18 components or have 18 errors in one of the step/steps from six steps (server/client activity, cookie, contents in the request/response), all incorrect or did not attempt.
Consider a scenario where an advertising company pays fees to Deakin University for including banner ads in Deakin’s web site, i.e., an image presenting an advertisement of a product from a manufacturer which is linked to the manufacturer’sweb server. Deakin receives payment from the advertising company based on the number of visits by its users to the manufacturer’s web site. The advertising company gets payment from the manufacturer based on the number of times the advertisement is displayed. Prepare a diagram illustrating how the cookie is used when retrieving a Deakin web page containing an advertisement and then tracking the users of Deakin’s web site visiting the manufacturer’s web site by clicking on an advertisement. Explain the steps in your diagram.
Overall Explanations and diagram:
Explained clearly all four steps (source and destination of each step form different server/client, contents in the request/response) and presented in the diagram
Explained but missing two components or have two errors from (source and destination of each step form different server/client, contents in the request/response) in one of the step/steps from four steps and presented in the diagram. 
Explained but missing 4 components or have 4 errors from (source and destination of each step form different server/client, contents in the request/response) in one of the step/steps from four steps and presented in the diagram. 
Explained but missing 6 components or have 6 errors from (source and destination of each step form different server/client, contents in the request/response) in one of the step/steps from four steps and presented in the diagram.

Explained but missing 8 components or have 8 errors from (source and destination of each step form different server/client, contents in the request/response) in one of the step/steps from four steps and presented in the diagram. o 3.0 Explained but missing 10 components or have 10 errors from (source and destination of each step form different server/client, contents in the request/response) in one of the step/steps from four steps and presented in the diagram. o 2.0 Explained but missing 12 components or have 12 errors from (source and destination of each step form different server/client, contents in the request/response) in one of the step/steps from four steps and presented in the diagram. o 1.0 Explained but missing 14 components or have 14 errors from (source and destination of each step form different server/client, contents in the request/response) in one of the step/steps from four steps and presented in the diagram. o 0.0 Explained but all incorrect or did not attempt.
In the following diagram, a web client is communicating with a web server which opens a TCP connection at client’s end. The client is using an initial sequence number (ISN) 2048 with a port of 51000 and receiving window size of 2000. In response, server also opens a TCP connection with ISN 21732 and receiving window size of 4000, port 80. After connection establishment, client sends two data segments each of size 500 bytes. Then server responds in a single segment with 1000 bytes. Then client closes the connection, in response server also closes the connection.
Show all TCP segments during connection establishment, data transfer and connection termination between client and server (no segments are corrupted/dropped in the exchange). For each segment, write header information which should include port number, sequence number, acknowledgement number, values of all bits in the control field, window sizes and ranges of data bytes in the data section(as appropriate for the segment type). Each segment needs to be placed in a separate table. First row in the table should mention the label of segment based on their type and direction clearly client to server or vice versa. All tables should have a number at the beginning (on top of the table) which indicates the order they are sent by either the client or the server.
Marking guide line:
Marks for each segment-1.44, then each component marks=segment mark/number of component in the segment
1. Connection establishment (11 component + 13 component + 13 component)
2. Data transfer ( 15 component + 15 component + 15 component)
3. Connection termination ( 13 component + 13 component + 13 component)

Questin 1

1 a).

Six steps on how cookies are used in an online shopping.

Step 1:

The client who is our customer in this case, wants to get to boytoys.com site through http /1.1  where he/ she is redirected to the site’s server that is web server,. So a file has to be created in both sides, client side and webserver side with the same id (Lund et al., 2010).

Step 2:

In this step a cookie is set as the server responds to the client thus starting the session having the cookies header http / 1.1 200 OK , where the vendors file is saved in the client side together with the cookie having the same id as the client/customer file. To keep track of that specific customer or client so that when he tries to access that site again either to get something, it gets easier and faster. This cookie will be used to retrieve information about that specific customer whose cookie has been set, thus making the customer more visible and more so understandable. Thus keep updating the customer file saved in the vendor/web server side.

Step 3:

This cookie has now made the vendor able to distinguish customers according to their behaviors. The cookie which was set and session started in step 2, is attached to the client/customer requests which is very easy for the server to monitor the requests of the client because the cookie is already registered and is yet to expire (Jeffres and Lin, 2009). So the customer requests for an image which is sent together with the cookie. This cookie is identified by the vendor through the already set id.

 Step 4

Through that cookie the vendor is able to realize the customer’s need easily. In our case the vendor responds to the customer’s request with the price information having the cookies header http / 1.1 200 OK. So the cookie makes the interaction between vendor and the customer more efficient, due to its functionality of collecting customer information during that session. As the customer request for the page that has information [about pricing, the file (customer’s file) is updated.

Step 5:

The cookie is till used in this step to help the vendor or the web server recognize the customer. The same cookie is used in this step where the customer wants to know more about the payment of the item he/she viewed.

Step 6:

At this point, the vendor responds to the customer’s request payment information. The vendor response to the request that is about the order confirmation has a cookie header https:/1.1. Then the customer’s file is updated so that if the customer requires to log in next time, it would be very easy because the future request of the customer will have that unique ID attached to it (Pan and Xu ,2009). So it will continue residing in the customer side that is in his or her web browser as long as the cookies are not cleared.

Explanation of Cookie Use in Tracking Users and Displaying Advertisements

1 b)  . Generally, Banner ads are adverts that are usually exhibited on a page in a website. The adverts may be an image or text, graphics and sounds. Some people prefer advertisements to be inform of animation or static images.

These banner ads are usually links where by when clicked they will redirect you to another website or webpage which is advertising. So in our case, an advert is displayed on Deakin University website which is an image of a product from a manufacturer web server.

For an advert to be clicked by the visitor of a site, creativity is required, so that it is able to catch the attention of the web page viewer.

So for the advertising company to keep track of the clicks , cookies are a better option because they are even able to collect  the viewer behavior while online, and from these kind of information the advertiser is able to know what viewers need to see and it must be eye catching (Wang and Wei,  2012).

Four steps:

Step 1:

A website viewer or client wants to get to a Deakin’s web site, where the deskins web server loads the web page the viewer wants to view. That is GET: deakinuniversity.ac. In that web page, the advertising company has placed some adverts. While the viewer or the client gets to deskins web site, cookie with a unique id =9654 is saved at client side browser.

Step 2:

In this step, the client attention goes to a certain banner ad displayed on Deakin’s web site by the advertising company, after clicking the advert, the client id is synchronized and redirected to the manufacturer web site through the client web browser.

Step 3:

After the client is redirected to the manufacturer’s web site, a cookie is set with a unique id = a1 which is in turn saved in the client browser for future log in. Now, the client seems to be requesting get information about manufacturer from manufacturer web server.

Step 4:

Here, the client is able to view the manufacturer website, though he seems to have a new cookie id, it is the same with the previous one (Walther and Jang, 2012). So by use of these new cookies created, the advertising company is able to track clicks and visitors in the manufacturer’s website.

Question 2

2).  In table 1, table 2 , is where the connection is established while in table 4,and 5 ,the data transfer takes place and termination of the TCP connection occurs in table 6,7 and 8.

 ACK - Acknowledgement

 SYN - Synchronize sequence numbers

 FIN - End of data

Table 1: Client

Here, the client connect with port 51000. The client introduces SYN which has an initial sequence number 2048. Mostly, for acknowledgement number while establishing the TCP connection it is set to zero because it is not applicable in the SYN type of segment. In this case, it starts with a receiving window size of 2000 and also no data is yet to be transmitted and it can’t be before the connection is complete.

TCP Segments Exchange in a Client-Server Connection

Table 2: Server

Then, the server has to respond to the SYN sent by the client through port 80 and its window size is 4000. After receiving the SYN sent by the client, it sends back its initial sequence number (21732) and acknowledges the client initial sequence number by adding 1 to it resulting to 2049 as indicated in the table. This (2049) will be the sequence number, so the next bytes of data to be transmitted by the client will have it as the new sequence number.  Therefore, it is referred to as the SYN –ACK segment.

Table 3: Client

After the client receives SYN – ACK sent by the server trough port 51000, the client now is set to go , the session is active , so he / she starts transmitting the data to the server until the session ends. As the client transmits the data, ACKS are also used. When the client receives SYN – ACK, an acknowledgement number (ACK) is set to acknowledge where the server’s sequence number is increased by 1 that is (21732 + 1 = 21733) and is assumed to be the acknowledgement number (21733).  Client  transfers that data with the sequence number 2049 which is usually the first byte  that the client is transferring (Lin, 2008). As the data is being transmitted, the acknowledgement number 21733 is also sent where by it is the sequence number of the bytes of data that the server will transmit. In the table below, the client is to transmit 500 bytes of data as a single segment. In this case this the next expected number sequence will be 2049 + 500 = 2549. As you can see, the client now uses 4000 as the window size.

Table 4: Client

As in table 2 , the same process takes place where the client using port 51000 sends an acknowledgement together with the data it want to transfer because the connection is already established and the session is up and running. In our scenario the client is to send two data segments each of size 500 bytes and the server sends back as a single data segment of size 1000 bytes. Also in this segment   the client receives SYN – ACK, and acknowledges the server where the server’s sequence number is increased by 1 that is 21733 is set to be the acknowledgement number. The sequence number 2049 which is known to be the first data byte that the client is sending. As shown in the table, the window size of 4000 is still used, that was initially for server.

Table 5: Server

When the server receives all the acknowledgement segments of data size 500 each, it acknowledges those   data by transmitting back the sequence number 2549 as you can see in the table below in the acknowledgement number column thus accepting that the next data of bytes to be transmitted will start with sequence number 2549. (Braun., Münz and Carle, 2010) So each and every segment of data must have an acknowledgement. Here, the acknowledgement number is gotten by adding both data segments of size 500 bytes to the client sequence number (2049).

Table 6: Client

After the data transfer is complete the client application terminates the session by sending a FIN segment and then waits for an acknowledgement from the server.

Table 7: Server

When the server receives the FIN segment which is an indication of TCP termination , the server sends back the FIN  with an acknowledgement that is FIN + ACK to the client.

Table 8: Client

The client side only terminates the session when it receives and acknowledgment from the server.