Subject Name
Internet Fundamental and Applications

Code

COMP 113
INTERNET FUNDAMENTAL
&
Applications
Chapter II
By
D.Bal...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Network
• Network
one computer connected to more t...
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Internet Fundamental and Applications

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Advantages of networking
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Connectivity and Commu...
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Internet Fundamental and Applications

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Network

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• Network: A set of devices (nodes) conne...
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Internet Fundamental and Applications

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Type of Connection

D.Balaganesh Lincoln University College

Cre...
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Internet Fundamental and Applications

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Credit Hours

Type of Connection
• Point-to-point
– Dedicated li...
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Internet Fundamental and Applications

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Physical Topology

D.Balaganesh Lincoln University College

Cred...
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Internet Fundamental and Applications

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Mesh Topology
• Dedicated point-to-point link to
every other nod...
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Internet Fundamental and Applications

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Star Topology
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Dedicated point-to-point li...
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Internet Fundamental and Applications

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Bus Topology
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One long cable that links ...
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Internet Fundamental and Applications

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Ring Topology
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Dedicated point-to-point li...
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Internet Fundamental and Applications

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Hybrid Topology
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Example: Main star topology ...
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Internet Fundamental and Applications

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Categories of Networks

D.Balaganesh Lincoln University College
...
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Internet Fundamental and Applications

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LAN
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Usually privately owned
A network for a single offi...
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Internet Fundamental and Applications

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MAN
• Designed to extend to an entire city
• Cable TV network, a...
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Internet Fundamental and Applications

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Credit Hours

WAN
• Long distance transmission, e.g., a country,...
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Internet Fundamental and Applications

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Network Vs Internet
Internet
Network of network is called Intern...
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Internet Fundamental and Applications

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Internet programming language
E-m...
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Internet Fundamental and Applications

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The Internet
• Internet is a network of interconne...
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Internet Fundamental and Applications

Code

Credit Hours

The Advanced Research Projects Agency
Network
• In...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Internet Connections
Various technologies availabl...
Subject Name
Internet Fundamental and Applications

Code

D.Balaganesh Lincoln University College

Credit Hours
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Internet Connections
Broadband
A connection in whi...
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Internet Fundamental and Applications

Code

Data
• Analog data
– Voice
– Images
• Digital data
– Text
– Digi...
Subject Name
Internet Fundamental and Applications

Code

Modem

D.Balaganesh Lincoln University College

Credit Hours
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Analog Signaling
amplitude (volts)

1 cycle
• repr...
Subject Name
Internet Fundamental and Applications

Code

Three Components of Data
Communication

• Data
– Analog: Continu...
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Internet Fundamental and Applications

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Modem
• Anlog
• Digital
• Modulation
– Digital to analog convers...
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Internet Fundamental and Applications

Code

Credit Hours

Modem Internet Connections
• Dial-up connection vi...
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Internet Fundamental and Applications

•

Code

Credit Hours

Faster Internet Connections
ISDN (Integrated Se...
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Internet Fundamental and Applications

Code

Credit Hours

ISP (Internet Service Provider)
If you want to con...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Internet Service Provider (ISP)
• Provides interne...
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Internet Fundamental and Applications

Code

SERVICES OF INTERNET
•
•
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WWW
FTP
Telnet
E-mail

D.Balaganes...
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Internet Fundamental and Applications

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Credit Hours

What is the difference between the World Wide Web ...
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Internet Fundamental and Applications

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World Wide Web Basics

Files interconnected via hyper...
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Internet Fundamental and Applications

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FTP (File Transfer Protocol)
File Transfer Protoco...
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Internet Fundamental and Applications

Code

Credit Hours

The basic objectives of FTP are
• to give flexibil...
Subject Name
Internet Fundamental and Applications

Code

Telnet (Remote Computing)
• Telnet (Remote Computing)
Telnet or ...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

E-Mail (Electronic Mail)
E-mail or Electronic mail...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Voice Messaging
Voice Messaging
It is a new commun...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

E-Commerce
Electronic commerce or e-commerce as it...
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Internet Fundamental and Applications

Code

Internet Important Terms
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HTTP
URL
Hyperlink
Brows...
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Internet Fundamental and Applications

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HTTP (Hypertext Transfer Protocol)
• HTTP stands f...
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Internet Fundamental and Applications

Code

Credit Hours

URL (Uniform Resource Locator)
• The URL (Uniform ...
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Internet Fundamental and Applications

• URLWorld

Code

Credit Hours

Wide Web Basics

– No spaces and Case ...
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Internet Fundamental and Applications

Code

Credit Hours

Network Addresses
Hostname
A name made up of words...
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Internet Fundamental and Applications

Code

Credit Hours

Host number
Domain Name System
The part of the IP ...
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Internet Fundamental and Applications

Code

Domain Name System
matisse.csc.villanova.edu
Computer
name
Domai...
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Internet Fundamental and Applications

Code

Domain Name System

Figure 15.10 Top-level domains, including so...
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Internet Fundamental and Applications

Code

Credit Hours

Domain Namethan the United States
System
Organizat...
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Internet Fundamental and Applications

Code

Credit Hours

Domain Name System
Domain name system (DNS)
A dist...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Domain Name Addressing

• Domain names can include...
Subject Name
Internet Fundamental and Applications

Code

Uniform Resource Locators

Credit Hours

• The IP address and th...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Structure of a Uniform Resource Locators
pathname
...
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Internet Fundamental and Applications

Code

Credit Hours

Hyperlink
A hyperlink is a piece of text (or a gra...
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Internet Fundamental and Applications

Code

Credit Hours

What is a web browser?
Web browsing applications i...
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Internet Fundamental and Applications

Code

Credit Hours

• What are cookies?
• Some web sites can store hid...
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Internet Fundamental and Applications

Code

Credit Hours

What is an Internet cache?
Each time you display a...
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Internet Fundamental and Applications

Code

Credit Hours

SECURITY CONSIDERATIONS
• What is a digital certif...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

• What is encryption?
• Encryption is a means of '...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

• What is a firewall?
• A fire wall consists of so...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Modem Internet Connections
• Dial-up connection vi...
Subject Name
Internet Fundamental and Applications

•

Code

Credit Hours

Faster Internet Connections
ISDN (Integrated Se...
Subject Name
Internet Fundamental and Applications

Code

Network Layer

D.Balaganesh Lincoln University College

Credit H...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Layered Model: Sending a Letter

D.Balaganesh Linc...
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Internet Fundamental and Applications

•

Code

Credit Hours

OSI Model(Open Systems Interconnection)

ISO is...
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Internet Fundamental and Applications

•

Code

Credit Hours

Interaction between layers in the OSI model
Lay...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Physical Layer
• The physical layer is responsible...
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Internet Fundamental and Applications

Code

Physical Layer: Duties
• Physical characteristics of interfaces ...
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Internet Fundamental and Applications

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Credit Hours

Data Link Layer
• The data link layer is responsib...
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Internet Fundamental and Applications

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Data Link Layer: Duties
•
•
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Framing
Physical addressing
F...
Subject Name
Internet Fundamental and Applications

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Network Layer
• The network layer is responsible for the deliver...
Subject Name
Internet Fundamental and Applications

•

Code

Network Layer: Duties
Logical addressing and routing

D.Balag...
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Internet Fundamental and Applications

Code

Transport Layer
• The transport layer is responsible for deliver...
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Internet Fundamental and Applications

Code

Transport Layer: Duties
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•
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Service-point (port) addressi...
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Internet Fundamental and Applications

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Credit Hours

Reliable Process-to-Process Delivery of a Message
...
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Internet Fundamental and Applications

Code

Session Layer
• Session layer is responsible for dialog control ...
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Internet Fundamental and Applications

Code

Presentation Layer
• Presentation layer is responsible for trans...
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Internet Fundamental and Applications

Code

Credit Hours

Application Layer
• Application layer is responsib...
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Internet Fundamental and Applications

Code

Credit Hours

Application Layer: Services
•
•
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Network virtu...
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Internet Fundamental and Applications

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Summary of Layers

D.Balaganesh Lincoln University College

Cred...
Subject Name
Code
OSI
Internet Fundamental and Applications layer vs TCP/IP Layer

Credit Hours

TCP/IP PROTOCOL SUITE

To...
Subject Name
Internet original TCP/IP protocol
The Fundamental and Applications

Code

Credit Hours

suite was defined as ...
Subject Name
Internet Fundamental and Applications

Code

TCP/IP and OSI Model

D.Balaganesh Lincoln University College

C...
Subject Name
Internet Fundamental and Applications

Code

D.Balaganesh Lincoln University College

Credit Hours
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

TCP/IP Protocol Suite

• Host-to-network : Physica...
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Internet Fundamental and Applications

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•
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Code

Credit Hours

The Hypertext Transfer Protocol (H...
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Internet Fundamental and Applications

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Credit Hours

Addressing
• Four levels of addresses in TCP/IP pr...
Subject Name
Internet Fundamental and Applications

Code

Relationship of Layers and
Addresses

D.Balaganesh Lincoln Unive...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Physical Address
• A node with physical address 10...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Logical (IP) Address

• The physical addresses wil...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Port Address
• The physical addresses change from ...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

Specific Address
• Some application have user-frie...
Subject Name
Internet Fundamental and Applications

Code

Credit Hours

• Transmission Control Protocol (TCP)
User Datagra...
Subject Name
Internet Fundamental and Applications

Code

Internet Address Classes
•

Internet Address Classes:

•

IP dis...
Subject Name
Internet Fundamental and Applications
Lowest
First Octet
IP Address
Value of
of IP
Class
First Octet
Address
...
Subject Name
Internet Fundamental and Applications

•
•
•
•

Code

• Class A:
– For very large organizations
– 16 million ...
Subject Name
Internet Fundamental and Applications

Code

Internetwork

• Internetwork (internet) : two or more networks a...
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Comp 111 cep ii

  1. 1. Subject Name Internet Fundamental and Applications Code COMP 113 INTERNET FUNDAMENTAL & Applications Chapter II By D.Balaganesh D.Balaganesh Lincoln University College Credit Hours
  2. 2. Subject Name Internet Fundamental and Applications Code Credit Hours Network • Network one computer connected to more then one computer is called Network D.Balaganesh Lincoln University College
  3. 3. Subject Name Internet Fundamental and Applications Code Advantages of networking • • • • • • • • Connectivity and Communication Data Sharing Hardware Sharing Internet Access Internet Access Sharing Data Security and Management Performance Enhancement and Balancing Entertainment D.Balaganesh Lincoln University College Credit Hours
  4. 4. Subject Name Internet Fundamental and Applications Code Network Credit Hours • Network: A set of devices (nodes) connected by communication links • Node: Computer, printer, or any device capable of sending and/or receiving data • To be considered effective and efficient, a network must meet a number of criteria D.Balaganesh Lincoln University College
  5. 5. Subject Name Internet Fundamental and Applications Code Type of Connection D.Balaganesh Lincoln University College Credit Hours
  6. 6. Subject Name Internet Fundamental and Applications Code Credit Hours Type of Connection • Point-to-point – Dedicated link between two devices – The entire capacity of the channel is reserved – Ex) Microwave link, TV remote control • Multipoint – More than two devices share a single link – Capacity of the channel is either • Spatially shared: Devices can use the link simultaneously • Timeshare: Users take turns D.Balaganesh Lincoln University College
  7. 7. Subject Name Internet Fundamental and Applications Code Physical Topology D.Balaganesh Lincoln University College Credit Hours
  8. 8. Subject Name Internet Fundamental and Applications Code Mesh Topology • Dedicated point-to-point link to every other nodes • A mesh network with n nodes has n(n-1)/2 links. A node has n-1 I/O ports (links) • Advantages: No traffic problems, robust, security, easy fault identification & isolation • Disadvantages: Difficult installation/reconfiguration, space, cost D.Balaganesh Lincoln University College Credit Hours
  9. 9. Subject Name Internet Fundamental and Applications Code Credit Hours Star Topology • • • • Dedicated point-to-point link only to a central controller, called a hub Hub acts as an exchange: No direct traffic between devices Advantages: Less expensive, robust Disadvantages: dependency of the whole on one single point, the hub D.Balaganesh Lincoln University College
  10. 10. Subject Name Internet Fundamental and Applications Code Credit Hours Bus Topology • • • • • One long cable that links all nodes tap, drop line, cable end limit on the # of devices, distance between nodes Advantages: Easy installation, cheap Disadvantages: Difficult reconfiguration, no fault isolation, a fault or break in the bus stops all transmission D.Balaganesh Lincoln University College
  11. 11. Subject Name Internet Fundamental and Applications Code Credit Hours Ring Topology • • • • Dedicated point-to-point link only with the two nodes on each sides One direction, repeater Advantages: Easy reconfiguration, fault isolation Disadvantage: Unidirectional traffic, a break in the ring cab disable the entire network D.Balaganesh Lincoln University College
  12. 12. Subject Name Internet Fundamental and Applications Code Credit Hours Hybrid Topology • • Example: Main star topology with each branch connecting several stations in a bus topology To share the advantages from various topologies D.Balaganesh Lincoln University College
  13. 13. Subject Name Internet Fundamental and Applications Code Categories of Networks D.Balaganesh Lincoln University College Credit Hours
  14. 14. Subject Name Internet Fundamental and Applications Code LAN • • • • Usually privately owned A network for a single office, building, or campus a few Km Common LAN topologies: bus, ring, star An isolated LAN connecting 12 computers to a hub in a closet D.Balaganesh Lincoln University College Credit Hours
  15. 15. Subject Name Internet Fundamental and Applications Code MAN • Designed to extend to an entire city • Cable TV network, a company’s connected LANs • Owned by a private or a public company D.Balaganesh Lincoln University College Credit Hours
  16. 16. Subject Name Internet Fundamental and Applications Code Credit Hours WAN • Long distance transmission, e.g., a country, a continent, the world • Enterprise network: A WAN that is owned and used by one company D.Balaganesh Lincoln University College
  17. 17. Subject Name Internet Fundamental and Applications Code Network Vs Internet Internet Network of network is called Internet D.Balaganesh Lincoln University College Credit Hours
  18. 18. Subject Name Internet Fundamental and Applications • • • • • • • • Code Credit Hours Internet programming language E-mail Internet SMS(short message service) Social networking sites Websites Blog - Share your life's stories, videos and photos VOIP - Voice over Internet Protocol Podcast - type of digital media consisting of an episodic series of audio, video, PDF • Rss(Really simple Syndication) its security bulletins, advisories, magazine related alerts for IT professionals. TechNet provides RSS feeds for features, and other security- D.Balaganesh Lincoln University College
  19. 19. Subject Name Internet Fundamental and Applications Code Credit Hours The Internet • Internet is a network of interconnected computers that is now global • Internet born in 1969 - called ARPANET • 1969 ARPANET was connection of computers at UCLA, Stanford, UCSB, Univ. of Utah D.Balaganesh Lincoln University College
  20. 20. Subject Name Internet Fundamental and Applications Code Credit Hours The Advanced Research Projects Agency Network • In 1969, the U.S. Defence Department funded a project to develop a network, which can withstand the bombing. Basically the idea was to develop a very secure network which can work even after a nuclear attack. This project was known as ARPANET. D.Balaganesh Lincoln University College
  21. 21. Subject Name Internet Fundamental and Applications Code Credit Hours Internet Connections Various technologies available to connect a home computer to the Internet Phone modem converts computer data into an analog audio signal for transfer over a telephone line, and then a modem at the destination converts it back again into data Digital subscriber line (DSL) uses regular copper phone lines to transfer digital data to and from the phone company’s central office Cable modem uses the same line that your cable TV signals come in on to transfer the data back and forth D.Balaganesh Lincoln University College
  22. 22. Subject Name Internet Fundamental and Applications Code D.Balaganesh Lincoln University College Credit Hours
  23. 23. Subject Name Internet Fundamental and Applications Code Credit Hours Internet Connections Broadband A connection in which transfer speeds are faster than 768 kilobits per second – DSL connections and cable modems are broadband connections – The speed for downloads (getting data from the Internet to your home computer) may not be the same as uploads (sending data from your home computer to the Internet) D.Balaganesh Lincoln University College
  24. 24. Subject Name Internet Fundamental and Applications Code Data • Analog data – Voice – Images • Digital data – Text – Digitized voice or images D.Balaganesh Lincoln University College Credit Hours
  25. 25. Subject Name Internet Fundamental and Applications Code Modem D.Balaganesh Lincoln University College Credit Hours
  26. 26. Subject Name Internet Fundamental and Applications Code Credit Hours Analog Signaling amplitude (volts) 1 cycle • represented by sine waves phase difference time (sec) frequency (hertz) = cycles per second D.Balaganesh Lincoln University College
  27. 27. Subject Name Internet Fundamental and Applications Code Three Components of Data Communication • Data – Analog: Continuous value data (sound, light, temperature) – Digital: Discrete value (text, integers, symbols) • Signal – Analog: Continuously varying electromagnetic wave – Digital: Series of voltage pulses (square wave) • Transmission – Analog: Works the same for analog or digital signals – Digital: Used only with digital signals D.Balaganesh Lincoln University College Credit Hours
  28. 28. Subject Name Internet Fundamental and Applications Code Modem • Anlog • Digital • Modulation – Digital to analog conversion • Demodulation – Analog to Digital Conversion Modulation and demodulation is called Modem D.Balaganesh Lincoln University College Credit Hours
  29. 29. Subject Name Internet Fundamental and Applications Code Credit Hours Modem Internet Connections • Dial-up connection via modem (56K) • Cable modems – Network card and cable modem required – Always-on and 25 times faster than dial-up D.Balaganesh Lincoln University College
  30. 30. Subject Name Internet Fundamental and Applications • Code Credit Hours Faster Internet Connections ISDN (Integrated Services Digital Network) – 64K or 128K – Always-on and expensive • DSL (Digital Subscriber Line) – Up to 125 times faster than dialup • DSS (Digital Satellite Service) – 500K Need proximity to a telephone switching station D.Balaganesh Lincoln University College
  31. 31. Subject Name Internet Fundamental and Applications Code Credit Hours ISP (Internet Service Provider) If you want to connect to the Internet, you need to subscribe via an Internet Service Provider. The ISP gives you a connection to the Internet either via your telephone line or via a special digital high speed line. An example of a popular ISP is AOL (America On-Line). D.Balaganesh Lincoln University College
  32. 32. Subject Name Internet Fundamental and Applications Code Credit Hours Internet Service Provider (ISP) • Provides internet access to businesses, • • • • • organizations and individuals Provides telecommunications equipment User ID and password required Connects you to backbone E-mail account monthly fee Should have local access telephone numbers D.Balaganesh Lincoln University College
  33. 33. Subject Name Internet Fundamental and Applications Code SERVICES OF INTERNET • • • • WWW FTP Telnet E-mail D.Balaganesh Lincoln University College Credit Hours
  34. 34. Subject Name Internet Fundamental and Applications Code Credit Hours What is the difference between the World Wide Web (WWW) and the Internet? WWW is the acronym for the World Wide Web. It is also commonly known as ‘The Web’. The WWW is hypertext based information retrieval tool • The World Wide Web (WWW) is just a small part of the Internet as a whole. • The Internet, relates to all the hardware and software involved, and as well as including the WWW, also includes FTP (File Transfer Protocol – more about this later), email and newsgroups. • The WWW is basically the text and pictures which you can view using your web browser, such as Microsoft Internet Explorer, or Netscape Navigator. D.Balaganesh Lincoln University College
  35. 35. Subject Name Internet Fundamental and Applications • • • • • Code World Wide Web Basics Files interconnected via hypertext Web pages make up a web site Home Page Links or hyperlinks Web servers D.Balaganesh Lincoln University College Credit Hours
  36. 36. Subject Name Internet Fundamental and Applications Code Credit Hours FTP (File Transfer Protocol) File Transfer Protocol, is an Internet utility software used to upload and download files. It gives access to directories or folders on remote computers and allows software, data and text files to be transferred between different kinds of computers. • FTP is just a way of transferring data from one place to another over the Internet. If is often used for downloading large files from a web site. You do not really need to know anything about how it works, in most cases you willclick on a link within a web page, and your web browser (such as Microsoft Internet Explorer) will take care of the FTP transfer for you, all you have to decide is where to store the file which you wish to D.Balaganesh Lincoln University College download.
  37. 37. Subject Name Internet Fundamental and Applications Code Credit Hours The basic objectives of FTP are • to give flexibility and promote sharing of computer programs, files and data • to transfer data reliably and more efficiently over network • to encourage implicit or indirect use of remote computers using Internet • to shield a user from variations in file storage systems among hosts D.Balaganesh Lincoln University College
  38. 38. Subject Name Internet Fundamental and Applications Code Telnet (Remote Computing) • Telnet (Remote Computing) Telnet or remote computing is telecommunication utility software, which uses available telecommunication facility and allows you to become a user on a remote computer. Once you gain access to the remote computer, you can use it for the intended purpose. The TELNET works in a very step by step procedure. The commands typed on the client computer are sent to the local Internet Service Provider (ISP), and then from the ISP to the remote computer that you have gained access. Most of the ISP provides facility to TELENET into your own account from another city and check your e-mail while you are traveling or away on business College D.Balaganesh Lincoln University Credit Hours
  39. 39. Subject Name Internet Fundamental and Applications Code Credit Hours E-Mail (Electronic Mail) E-mail or Electronic mail is a paperless method of sending messages, notes or letters from one person to another or even many people at the same time via Internet. E-mail is very fast compared to the normal post. E-mail messages usually take only few seconds to arrive at their destination Features of E-mail: • One-to-one or one-to-many communications • Instant communications • Physical presence of recipient is not required • Most inexpensive mail services, 24-hours a day and seven days a week • Encourages informal communications D.Balaganesh Lincoln University College
  40. 40. Subject Name Internet Fundamental and Applications Code Credit Hours Voice Messaging Voice Messaging It is a new communication approach which is similar to electronic mail except that it is audio message rather than text messages that are processed. A sender speaks into a telephone rather than typing, giving the name of the recipient and the message. That sender's voice signal is then digitalised and stored. The system can then either deliver the message at a specified time in future or it can be retrieved from a database by the recipient. D.Balaganesh Lincoln University College
  41. 41. Subject Name Internet Fundamental and Applications Code Credit Hours E-Commerce Electronic commerce or e-commerce as it is popularly known refers to the paperless exchange of business information using Electronic Data Interchange, Electronic mail, Electronic Bulletin Boards, Electronic Fund Transfer and other network based technologies. Electronic Commerce (EC) not only automates manual process and paper transactions, but it also helps organisations to move into a fully electronic environment and change the way they usually operate. D.Balaganesh Lincoln University College
  42. 42. Subject Name Internet Fundamental and Applications Code Internet Important Terms • • • • • • • HTTP URL Hyperlink Browser Cookies Internet cache SECURITY D.Balaganesh Lincoln University College Credit Hours
  43. 43. Subject Name Internet Fundamental and Applications Code Credit Hours HTTP (Hypertext Transfer Protocol) • HTTP stands for Hypertext Transfer Protocol. This is the language your web browser uses to request pages & graphics from the web server. You can see that your web browser is using the HTTP protocol when it is shown at the start of a web address such as http://www.yahoo.com D.Balaganesh Lincoln University College
  44. 44. Subject Name Internet Fundamental and Applications Code Credit Hours URL (Uniform Resource Locator) • The URL (Uniform Resource Locator) is just another name for a web address. • The URL consists of the name of the protocol (usually HTTP or FTP) followed by the address of the computer you want to connect to, e.g. a URL of “ftp://ftp.cdrom.com” would instruct your web browser to use the FTP protocol to connect to the computer called ftp.cdrom.com. D.Balaganesh Lincoln University College
  45. 45. Subject Name Internet Fundamental and Applications • URLWorld Code Credit Hours Wide Web Basics – No spaces and Case sensitive – HTTP (Hypertext Transfer Protocol) • HTML (Hypertext Markup Language) – .htm or .html file extension http://www.cnn.com/showbiz/movies.htm Web protocol standard Web Folder server D.Balaganesh Lincoln Universityname College name Document name and filename extension
  46. 46. Subject Name Internet Fundamental and Applications Code Credit Hours Network Addresses Hostname A name made up of words separated by dots that uniquely identifies a computer on the Internet IP address An address made up of four one-byte numeric values separated by dots that uniquely identifies a computer on the Internet Is there a correspondence between the parts of a hostname and an IP address? D.Balaganesh Lincoln University College
  47. 47. Subject Name Internet Fundamental and Applications Code Credit Hours Host number Domain Name System The part of the IP address that specifies a particular host (machine) on the network Yes, but what is it? Domain name The part of a hostname that specifies a specific organization or group Top-level domain (TLD) The last section of a domain name that specifies the type of organization or its country of origin D.Balaganesh Lincoln University College
  48. 48. Subject Name Internet Fundamental and Applications Code Domain Name System matisse.csc.villanova.edu Computer name Domain name TLD D.Balaganesh Lincoln University College Credit Hours
  49. 49. Subject Name Internet Fundamental and Applications Code Domain Name System Figure 15.10 Top-level domains, including some relatively new ones D.Balaganesh Lincoln University College Credit Hours
  50. 50. Subject Name Internet Fundamental and Applications Code Credit Hours Domain Namethan the United States System Organizations based in countries other use a top-level domain that corresponds to their two-letter country codes Do you email someone in another country? Figure 15.11 Some of the top-level domain names based on country codes D.Balaganesh Lincoln University College
  51. 51. Subject Name Internet Fundamental and Applications Code Credit Hours Domain Name System Domain name system (DNS) A distributed system for managing hostname resolution Domain name server A computer that attempts to translate a hostname into an IP address Should the tables containing hostname/IP mappings be sorted or unsorted? Why? D.Balaganesh Lincoln University College
  52. 52. Subject Name Internet Fundamental and Applications Code Credit Hours Domain Name Addressing • Domain names can include any number of parts separated by periods, however most domain names currently in use have only three or four parts. • Domain names follow hierarchical model that you can follow from top to bottom if you read the name from the right to the left. • For example, the domain name gsb.uchicago.edu is the computer connected to the Internet at the Graduate School of Business (gsb), which is an academic unit of the University of Chicago (uchicago), which is an educational institution (edu). • No other computer on the Internet has the same domain name. D.Balaganesh Lincoln University College
  53. 53. Subject Name Internet Fundamental and Applications Code Uniform Resource Locators Credit Hours • The IP address and the domain name each identify a particular computer on the Internet. • However, they do not indicate where a Web page’s HTML document resides on that computer. • To identify a Web pages exact location, Web browsers rely on Uniform Resource Locator (URL). • URL is a four-part addressing scheme that tells the Web browser:  What transfer protocol to use for transporting the file  The domain name of the computer on which the file resides  The pathname of the folder or directory on the computer on which the file resides  The name of the file D.Balaganesh Lincoln University College
  54. 54. Subject Name Internet Fundamental and Applications Code Credit Hours Structure of a Uniform Resource Locators pathname protocol http://www.chicagosymphony.org/civicconcerts/index.htm Domain name http => Hypertext Transfer Protocol D.Balaganesh Lincoln University College filename
  55. 55. Subject Name Internet Fundamental and Applications Code Credit Hours Hyperlink A hyperlink is a piece of text (or a graphic) on a Web page, which when clicked on will automatically: - Take you to a different part of the same page - Take you to a different page within the Web site D.Balaganesh Lincoln University College
  56. 56. Subject Name Internet Fundamental and Applications Code Credit Hours What is a web browser? Web browsing applications include ‘Internet Explorer’ (from Microsoft) and ‘Netscape Navigator/Communicator’. In both cases there are many different versions, and you will find that the later versions offer much more versatility as well as a better range of built-in features. The web browser allows you to view web pages D.Balaganesh Lincoln University College
  57. 57. Subject Name Internet Fundamental and Applications Code Credit Hours • What are cookies? • Some web sites can store hidden information about you on your hard disk using cookies. This information is stored in small text file. Cookies can be useful, for instance, a site may store your preferences about a web site, so that when you re-visit the site your preferences can be accessed automatically. Cookies are used by some web sites to identify you; this saves you having to “log in” to the web site each time you visit. D.Balaganesh Lincoln University College
  58. 58. Subject Name Internet Fundamental and Applications Code Credit Hours What is an Internet cache? Each time you display a web site within your web browser, a copy of the information (both text and pictures) is saved on your hard disk. The reason for this is that the next time you want to re-visit the site, the information is quickly loaded from the copy on your hard disk, rather than slowly from the actual Internet site. • As pictures are stored in the cache, if you are visiting a site which has many separate web pages, with say a company logo on each page, then all subsequent pages from that site will load a little faster as the logo graphics will load from the cache, not via the Internet D.Balaganesh Lincoln University College
  59. 59. Subject Name Internet Fundamental and Applications Code Credit Hours SECURITY CONSIDERATIONS • What is a digital certificate? • A digital certificate is used to encrypt information for secure transmission across the Internet. A digital certificate can be used to create a digital signature for an email, the signature guarantees the identity of sender, and it also ensures that the message cannot be tampered with in transit. A digital certificate can be purchased from a certificate authority such as www.verisign.com who will verify your identity. Digital certificates are used by Internet based shopping web sites to encrypt your credit card details so they cannot be intercepted as they travel the Internet. You can view the digital certificate for a secure web site by double clicking on the padlock in the web browser status bar, e.g. https://www.paypal.com D.Balaganesh Lincoln University College
  60. 60. Subject Name Internet Fundamental and Applications Code Credit Hours • What is encryption? • Encryption is a means of 'scrambling' an email message. It is used to make a message more secure, so that only the intended recipient of the message will be able to read the message. There are many means of enabling this encryption, both via hardware and software. A famous encryption program is called PGP(Pretty Good Privacy) D.Balaganesh Lincoln University College
  61. 61. Subject Name Internet Fundamental and Applications Code Credit Hours • What is a firewall? • A fire wall consists of software and hardware protection against invasion via the Internet. In most larger companies any connection to the Internet automatically goes through a firewall which would have been installed and customised by the companies technical IT team. In most cases you will be unaware of the firewall existence. D.Balaganesh Lincoln University College
  62. 62. Subject Name Internet Fundamental and Applications Code Credit Hours Modem Internet Connections • Dial-up connection via modem (56K) • Cable modems – Network card and cable modem required – Always-on and 25 times faster than dial-up D.Balaganesh Lincoln University College
  63. 63. Subject Name Internet Fundamental and Applications • Code Credit Hours Faster Internet Connections ISDN (Integrated Services Digital Network) – 64K or 128K – Always-on and expensive • DSL (Digital Subscriber Line) – Up to 125 times faster than dialup • DSS (Digital Satellite Service) – 500K Need proximity to a telephone switching station D.Balaganesh Lincoln University College
  64. 64. Subject Name Internet Fundamental and Applications Code Network Layer D.Balaganesh Lincoln University College Credit Hours
  65. 65. Subject Name Internet Fundamental and Applications Code Credit Hours Layered Model: Sending a Letter D.Balaganesh Lincoln University College
  66. 66. Subject Name Internet Fundamental and Applications • Code Credit Hours OSI Model(Open Systems Interconnection) ISO is the organization. OSI is the model D.Balaganesh Lincoln University College
  67. 67. Subject Name Internet Fundamental and Applications • Code Credit Hours Interaction between layers in the OSI model Layer and interface D.Balaganesh Lincoln University College
  68. 68. Subject Name Internet Fundamental and Applications Code Credit Hours Physical Layer • The physical layer is responsible for movements of individual bits from one hop (node) to the next • Mechanical and electrical specification, the procedures and functions D.Balaganesh Lincoln University College
  69. 69. Subject Name Internet Fundamental and Applications Code Physical Layer: Duties • Physical characteristics of interfaces and media • Representation of bits • Data rate • Synchronization of bits • Line configuration • Physical topology • Transmission mode D.Balaganesh Lincoln University College Credit Hours
  70. 70. Subject Name Internet Fundamental and Applications Code Credit Hours Data Link Layer • The data link layer is responsible for moving frames from one hop (node) to the next • Transform the physical layer to a reliable (error-free) link D.Balaganesh Lincoln University College
  71. 71. Subject Name Internet Fundamental and Applications Code Data Link Layer: Duties • • • • • Framing Physical addressing Flow control Error control Access control D.Balaganesh Lincoln University College Credit Hours
  72. 72. Subject Name Internet Fundamental and Applications Code Network Layer • The network layer is responsible for the delivery of packets from the source host to the destination host D.Balaganesh Lincoln University College Credit Hours
  73. 73. Subject Name Internet Fundamental and Applications • Code Network Layer: Duties Logical addressing and routing D.Balaganesh Lincoln University College Credit Hours
  74. 74. Subject Name Internet Fundamental and Applications Code Transport Layer • The transport layer is responsible for delivery of a message from one process to another D.Balaganesh Lincoln University College Credit Hours
  75. 75. Subject Name Internet Fundamental and Applications Code Transport Layer: Duties • • • • • Service-point (port) addressing Segmentation and reassembly Connection control Flow control Error control D.Balaganesh Lincoln University College Credit Hours
  76. 76. Subject Name Internet Fundamental and Applications Code Credit Hours Reliable Process-to-Process Delivery of a Message D.Balaganesh Lincoln University College
  77. 77. Subject Name Internet Fundamental and Applications Code Session Layer • Session layer is responsible for dialog control and synchronization D.Balaganesh Lincoln University College Credit Hours
  78. 78. Subject Name Internet Fundamental and Applications Code Presentation Layer • Presentation layer is responsible for translation, compression, and encryption D.Balaganesh Lincoln University College Credit Hours
  79. 79. Subject Name Internet Fundamental and Applications Code Credit Hours Application Layer • Application layer is responsible for providing services to the user D.Balaganesh Lincoln University College
  80. 80. Subject Name Internet Fundamental and Applications Code Credit Hours Application Layer: Services • • • • Network virtual terminal Mail services File transfer, access, and management Directory services D.Balaganesh Lincoln University College
  81. 81. Subject Name Internet Fundamental and Applications Code Summary of Layers D.Balaganesh Lincoln University College Credit Hours
  82. 82. Subject Name Code OSI Internet Fundamental and Applications layer vs TCP/IP Layer Credit Hours TCP/IP PROTOCOL SUITE To divide the services required to perform a task, the Internet has created a set of rules called protocols. These allow different local and wide area networks, using different technologies, to be connected together and carry a message from one point to another. The set, or suite, of protocols that controls the Internet today is referred to as the TCP/IP protocol suite. The abbreviations (TCP and IP) will become clear as we explain different protocols. D.Balaganesh Lincoln University College
  83. 83. Subject Name Internet original TCP/IP protocol The Fundamental and Applications Code Credit Hours suite was defined as having four layers: host-to-network (or link), internet (network), transport and application. The TCP/IP protocol suite D.Balaganesh Lincoln University College
  84. 84. Subject Name Internet Fundamental and Applications Code TCP/IP and OSI Model D.Balaganesh Lincoln University College Credit Hours
  85. 85. Subject Name Internet Fundamental and Applications Code D.Balaganesh Lincoln University College Credit Hours
  86. 86. Subject Name Internet Fundamental and Applications Code Credit Hours TCP/IP Protocol Suite • Host-to-network : Physical and data link layer – No specific protocol • Network layer – IP(Internet Protocl), ARP(Address Resolution Protocol), RARP(Reverse ARP), ICMP(Internet Control Message Protocol), IGMO(Internet Group Message Protocol) • Transport layer – TCP(Transmission Control Protocol), UDP(User Datagram Protocl), SCTP(Stream Control Transmission Protocol), • Application Layer – Combined session, presentation, and application layers D.Balaganesh Lincoln University College
  87. 87. Subject Name Internet Fundamental and Applications • • • • • • • Code Credit Hours The Hypertext Transfer Protocol (HTTP) transfers files that make up pages on the World Wide Web. The File Transfer Protocol (FTP) transfers individual files, typically for an interactive user session. The Simple Mail Transfer Protocol (SMTP) transfers mail messages and attachments. Additionally, the following Application layer protocols help you use and manage TCP/IP networks: The Domain Name System (DNS) protocol resolves a host name, such as www.microsoft.com, to an IP address and copies name information between DNS servers. The Routing Information Protocol (RIP) is a protocol that routers use to exchange routing information on an IP network. The Simple Network Management Protocol (SNMP) collects and exchanges network management information between a network management console and D.Balaganesh Lincoln and servers. network devices such as routers, bridges,University College
  88. 88. Subject Name Internet Fundamental and Applications Code Credit Hours Addressing • Four levels of addresses in TCP/IP protocols • Physical (link), logical (IP, network), port, and specific addresses D.Balaganesh Lincoln University College
  89. 89. Subject Name Internet Fundamental and Applications Code Relationship of Layers and Addresses D.Balaganesh Lincoln University College Credit Hours
  90. 90. Subject Name Internet Fundamental and Applications Code Credit Hours Physical Address • A node with physical address 10 sends a frame to a node with physical address 87. The two nodes are connected by a link (bus topology LAN). As the figure shows, the computer with physical address 10 is the sender, and the computer with physical address 87 is the receiver. 07:01:02:01:2C:4B A 6-byte (12 hexadecimal digits) physical address. D.Balaganesh Lincoln University College
  91. 91. Subject Name Internet Fundamental and Applications Code Credit Hours Logical (IP) Address • The physical addresses will change from hop to hop, but the logical addresses usually remain the same D.Balaganesh Lincoln University College
  92. 92. Subject Name Internet Fundamental and Applications Code Credit Hours Port Address • The physical addresses change from hop to hop, but the logical and port addresses usually remain the same D.Balaganesh Lincoln University College
  93. 93. Subject Name Internet Fundamental and Applications Code Credit Hours Specific Address • Some application have user-friendly addresses that are designed for that specific address • Example 1: e-mail address: kchung@kw.ac.kr – Defines the recipient of an e-mail • Example 2: URL (Universal Resource Locator) : www.kbs.co.kr – Used to find a document on the WWW D.Balaganesh Lincoln University College
  94. 94. Subject Name Internet Fundamental and Applications Code Credit Hours • Transmission Control Protocol (TCP) User Datagram Protocol (UDP) • • • • • • • • • • Asynchronous Transfer Mode (ATM). The Address Resolution Protocol (ARP) resolves the Internet layer address to a Network Interface layer address such as a hardware address. The Internet Protocol (IP) is a routable protocol that addresses, routes, fragments, and reassembles packets. The Internet Control Message Protocol (ICMP) reports errors and other information to help you diagnose unsuccessful packet delivery. The Internet Group Management Protocol (IGMP) manages IP multicast groups. For more information about the core protocols for the IPv4 Internet layer, see "IPv4 Internet Layer" later in this chapter. The core protocols for the IPv6 Internet layer consist of the following: IPv6 is a routable protocol that addresses and routes packets. The Internet Control Message Protocol for IPv6 (ICMPv6) reports errors and other information to help you diagnose unsuccessful packet delivery. The Neighbor Discovery (ND) protocol manages the interactions between neighboring IPv6 nodes. D.Balaganesh Lincoln University College The Multicast Listener Discovery (MLD) protocol manages IPv6 multicast groups.
  95. 95. Subject Name Internet Fundamental and Applications Code Internet Address Classes • Internet Address Classes: • IP distinguishes 5 classes of addresses. • IP Address classes D.Balaganesh Lincoln University College Credit Hours
  96. 96. Subject Name Internet Fundamental and Applications Lowest First Octet IP Address Value of of IP Class First Octet Address (binary) Class A Class B Class C Class D Class E 0xxx xxxx 10xx xxxx 110x xxxx 1110 xxxx 1111 xxxx 0000 0001 1000 0000 1100 0000 1110 0000 1111 0000 Code Highest Value of First Octet (binary) 0111 1110 1011 1111 1101 1111 1110 1111 1111 1111 Range of First Octet Values (decimal) 1 to 126 128 to 191 192 to 223 224 to 239 240 to 255 D.Balaganesh Lincoln University College Credit Hours Octets in Network ID / Host ID Theoretica l IP Address Range 1/3 1.0.0.0 to 126.255.25 5.255 2/2 128.0.0.0 to 191.255.25 5.255 3/1 192.0.0.0 to 223.255.25 5.255 — 224.0.0.0 to 239.255.25 5.255 — 240.0.0.0 to 255.255.25 5.255
  97. 97. Subject Name Internet Fundamental and Applications • • • • Code • Class A: – For very large organizations – 16 million hosts allowed • Class B: – – For large organizations – – 65 thousand hosts allowed • • Class C – – For small organizations – – 255 hosts allowed • • Class D – – Multicast addresses D.Balaganesh Lincoln University College – – No network/host hierarchy • Credit Hours
  98. 98. Subject Name Internet Fundamental and Applications Code Internetwork • Internetwork (internet) : two or more networks are connected by internetworking devices • Internetworking devices: router, gateway, etc. • The Internet: a specific worldwide network D.Balaganesh Lincoln University College Credit Hours

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