Lecture 6

Question 1

What is HTTP?

Answer 1

HTTP (Hypertext Transfer Protocol)
Hypertext documents are normally transferred between browsers and Web servers using the protocol known as HTTP
Browser gets documents from Web server
Documents identified by URL (Uniform Resource Locator)

Question 2

Different parts of an URL?

http://ssenterprise.aw.com/authors/shakespeare/Julius_Ceasar.html

Answer 2

Protocol=http
Host=ssenterprise.aw.com
Directory=authors/Shakespeare
Document Name=Julius_Ceasar.html

Question 3

HTML  CODES?
(Appearance:
<h1> =to start a level one heading
</h1><p>= to start a new paragraph
Links to other documents and content=
<a href=".">
Insert images:=
<img>
</a></p>)

Answer 3

(Appearance:
<h1> to start a level one heading
</h1><p> to start a new paragraph
Links to other documents and content:
<a href=".">
Insert images:
<img>
</a></p>)

Question 4

What is eXtensible Markup Language ?

Answer 4

XML: A language for constructing markup languages
Similar to HTML
But opens door to a World Wide Semantic Web

Question 5

Internet software levels?

Answer 5

Application: Constructs message with address
Transport: Chops message into packets
Network: Handles routing through the Internet
Link: Handles actual transmission of packets

Question 6

What is the TCP/IP Protocol ?

Answer 6

Transport Layer
TCP (transmission Control Protocol): establishes a connection before sending message, also has flow control and congestion control
UDP (User Datagram Protocol): merely sends the message to the address it was given and forgets about it
Network Layer (IP)
IPv4: 32-bit internet addressing system
IPv6: 128-bit internet addressing system

Question 7

Choosing between TCP and UDP

Answer 7

TCP- more reliable but less efficient

UDP-more efficient but less reliable

Question 8

Encryption?

Answer 8

Public-key Encryption
Public key: Used to encrypt messages
Private key: Used to decrypt messages