Part 1 Chapter 2: Communication and Internet Technologies
ii N ame two types of application that use the Domain Name System and for each give a brief description of how it is used. [4] b In the classful IPv4 addressing scheme, the 32-bit binary code for the address has the top (most significant) bit set to 0 if it is of class A, the top two bits set to 10 if class B or the top three bits set to 110 if class C. In a document an IPv4 address has been written as 205.124.16.152. i
Give the name for this notation for an IP address and explain how it relates to the 32-bit binary code. [2]
ii Identify the class of the address and explain your reason. [2] iii Explain why an IPv4 address defines a netID and a hostID. [3] c If the CIDR scheme for an IPv4 address is used the IP address 205.124.16.152 would be written as:
205.124.16.152/24
State the binary code for the hostID in this address with a reason. [2]
3 a A client–server web application has been developed which uses a file containing the following code: <!DOCTYPE html> <html> <body> <h1>We can give you an estimate of how many you will need if you are tiling a floor with our tiles. You need to tell us the length and the width of the room (in metres).</h1> <script> var length = prompt("enter the room length", ""); var width = prompt("enter the room width", ""); var tileSize = 0.25; var numberOfTiles = (length * width)/tileSize; alert ("The estimate for the number of tiles needed is " + numberOfTiles); </script> </body> </html>
i
Name the role of the person who would create this file. [1]
ii Identify where this file would be stored. [1] iii A browser is needed to run the application. State where the browser software is installed. [1] b
The file uses JavaScript. i
Identify two component parts of the file which involve JavaScript and explain their purpose. [4]
ii E xplain the sequence of events executed by the client computer and the web server when this application is used. [6]
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