Question:

(a) Consider that you enter the given URL in the address bar of a popular web client and that both the client and server accepts HTTP version 1.1.

i. What can be the initial request made by the client?

ii. Illustrate how HTTP version 1.1 allows 'surfing' experience to be greatly improved.

iii. Give a sample HTTP request message with at least four main header lines that is sent by the web client.

iv. Assume that the web resource is actually found on the server, give at least 3 header lines that you could expect in the sample response HTTP message.

(b) Authentication and Integrity are two important network security services.

i. Describe what you understand by authentication.

ii. Explain one mechanism that you could use to ensure data integrity alone during transmission.

(c) FTP is a popular protocol used to transfer files from one host to another.

i. Describe briefly how it works.
ii. Give three advantages that it has over HTTP for files transfer.

(d) In respect of the ISO/OSI Reference model,

i. Explain important functions handled by Layer 6.
ii. Describe advantage of the layered approach used by such a model.
iii. Illustrate disadvantages of having too many layers in a communication model.