Dec1999 NI222 : Networks and the Internet (Question 5)Suggested Solutions

(a)	Explain with a suitable example the purpose of specifying the scheme (i.e.the first component)in a URL address. The purpose of the scheme in URLs is to specify the protocol used to access the resource (1).Example: file,HTTP,or telnet (1).	[2]
(b)	Describe the pipelined and multi-threaded architectures used in improving the efficiency of the HTTP protocol in retrieving HTMLfiles. Pipeline: Web browsers can improve the performance by overlapping requests (1)and allowing parallel retrieval (1). Multi-threaded:this architecture allows Web servers to responds to several client requests simultaneously (2).	[4]
(c)	Write an HTML fragment for the label that appears when you book-mark a page as “The Centre of Learning",with a page heading “Informatics Computer School". <html><head> <title>The Centre of Learning </title> </head> <body> <h1>Informatics Computer School </h1> </body> </html> (1)for a suitable header;(1)for a suitable body.Candidates may include extra material without penalty (or reward),and may use upper or lower case for the tags. Candidates omitting the </body>and </html>should not be penalised.	[2]
(d)	What are the relative advantage and disadvantage of the logical and physical styles in HTML documents. Logical style:Help to enforce consistency throughout the page (or site)(1).Affect the page based on the configuration of browser (1). Physical style:Does not affect the page,when browser configuration is changed (1). Offer a different form of consistency by displaying the text the way it is tagged (1).	[4]
(e)	The power of HTML comes from its ability to link text and documents.Explain three main ways in which the links are used in HTML documents. Links to specific sections within a document (1).Links between sections of different documents (1).Link to send electronic mail to a specific person (1).	[3]