105 COSC - Networking and the Internet
Felix G. Hamza-Lup - Fundamentals of CS (COSC105)
1
Networks
What is a network?
Collection of computers and devices connected together to enable the transfer of data.
communications satellite
Classification of Networks
What is a network?
Collection of computers and devices connected together to enable the transfer of data.
communications satellite
Classification of Networks
What is a Local Area Network?
Network in limited geographical area such as a school computer laboratory, or office building
communications satellite
LAN
Classification of Networks
What is a Wide Area Network? Local Area Network?
Network in limited geographical area such as a school computer laboratory, or office building
communications satellite
LAN
Classification of Networks
What is a Wide Area Network? Network that covers large geographic area between cities or around the world
MAN
communications satellite
LAN WAN
Classification of Networks
What is a Wide Area Network? WLAN ? Network that covers large geographic area between cities or around the world
MAN
communications satellite
LAN WAN
Classification of Networks
What is a WLAN ? A wireless local area network "Wi Fi" Short range less than 300 ft
MAN
communications satellite
LAN
WLAN WAN
Classification of Networks Network Topologies
What is a WLAN ? A wireless local area network"Wi Fi" Short range less than 300 ft
MAN
communications satellite
WLAN WAN
Network Topologies
What is topology?
Pattern in which computers are connected
Bus
Ring
Wireless
Star Irregular
Network Topologies
What is Bridge?
Bus
Bridge
A computer or device that connect two networks of compatible type
Ring
Wireless
Star Irregular
Network Topologies
What is Router?
Bus
Bridge
A computer or device that connect two networks of different type
Router Router
Ring
Wireless
Star Irregular
An internet / Intranet Network Topologies
What is Router?
Bus
Bridge
A computer of device that connect two networks of different type
Router Router
Ring
Wireless
Star Irregular
An internet / Intranet
What is an internet?
Bus
Bridge
A set of inter-connected networks within a company/organization Also called Intranet
Router Router
Ring
Wireless
Star Irregular
An internet / Intranet The Internet
What is an internet?
Bus
Bridge
A set of inter-connected networks within a company/organization Also called Intranet
Router Router
Ring
Wireless
Star Irregular
The Internet
What is the Internet?
A world-wide collection of LANs and WANs linking millions of computers
Router Router Bridge
Client/Server Model
Client/Server Model Peer-to-Peer Distributed Systems:
Global information retrieval Accounting Inventory systems Reservation systems
The Internet
What is the Internet?
A world-wide collection of LANs and WANs linking millions of ARPANET computers
Origins ?
Goal: To allow scientists at different locations to share information
Networking project by Pentagon's Advanced Research Projects Agency (ARPA) Goal: To function if part of network were disabled
Became functional September 1969 4 Nodes
The Internet
What is the Internet?
A world-wide collection of LANs and WANs linking millions of ARPANET computers
Origins ?
Goal: To allow scientists at different locations to share information
Networking project by Pentagon's Advanced Research Projects Agency (ARPA) Goal: To function if part of network were disabled
Became functional September 1969 4 Nodes
The Internet
What are some internet programs? E-mail FTP
Games
Tank
Chat
Web
Instant messaging
Telnet
The Internet
What is some internet programs? are some classification of internet programs? E-mail FTP Client / Server Web
Instant messaging Games
Tank
Chat
Peer to Peer
Telnet
The Internet
What are some classification of internet programs? E-mail FTP Client / Server Web
Games
Tank
Chat
Peer to Peer
Instant messaging
Telnet
The Internet
How is a computer on the Internet addressed? Each computer or device connected to Internet is E-mail Chat assigned an: Internet protocol (IP) address FTP
IP address
199.95.72.10
Games
Tank
Web
first part identifies network
last part identifies specific computer Instant
messaging
Telnet
The Internet
What is a computerinstead Internet addressed? How can be used on the of an IP address? Each computer or device connected to Internet is A Domain Name E-mail Chat assigned an: Internet protocol (IP) address FTP
Web
IP address IP address Domain name part first
199.95.72.10 199.95.72.10 Games Tank last compsci.iup.edu part
Domain
identifies Specific network Computer
identifies specific Top Level computer Instant (TLD) Domain
A domain name server (DNS) maintains a Telnet directory of domain names and their IP
messaging
The Internet
What can be used instead of an IP address? A Domain Name E-mail
Chat 199.95.72.10 199.95.72.10 Games Tank compsci.iup.edu
Domain Top Level Instant (TLD) Domain
Web
IP address IP address Domain name
FTP
Specific Computer
A domain name server (DNS) maintains a Telnet directory of domain names and their IP
messaging
The Internet The World Wide Web
E-mail FTP
Games
Tank
Chat
Web
Instant messaging
Telnet
The World Wide Web
What is a Web Page ? A document written in HTML (Hypertext Markup Language).
<html> <body lang=EN-US link="#1818b7"> <div class=Section1> <p>SYLLABUS</p>
Web
Stored in a .html or .htm file
<p>COSC 105 Computer Science An Overview</p> <h2>Instructor</h2>
p. 2.9
The World Wide Web
How is a web page accessed?
Using a Universal Resource Locator (URL)
protocol domain name path
http://www.nationalgeographic.com/travel/index.html
The World Wide Web
What can pages web contain?
Graphics
<img src="http:// www.nationalgeographic.com/travel/Malloraca.gif">
The World Wide Web
What can web pages contain? Video
Consists of fullmotion images with sound played back at various speeds MPEG is popular video compression standard
streaming video
The World Wide Web
What else can web pages contain?
Controls
Used to communicate data and commands to a Web application
The World Wide Web
What else can web pages contain?
A hyperlink
A link to another web page associated with text, graphic, area of a graphic, or control.
<a href="http:// www.nationalgeographic.com/travel.html">
The World Wide Web
What can links reference?
Item found elsewhere on same Web page Different Web page at same Web site Web page at a different Web site
The World Wide Web
What is a Web Site ? A set of Web Pages stored at a given Domain
Web
p. 2.9
The World Wide Web
What is a XML ? A Mark-up language where the set of tags is extended Can convey semantic meaning
<?xml version="1.0" encoding="UTF-8"?> <SurveyPage SurveySessionID="ghjykoo" SurveyNo="10"> <SurveyItems> <SurveyItem ItemNo="5" ItemType="QuestionPP" QuestionNo="2"> <ItemText>Please indicate which class hours you would prefer<ItemText> </SurveyItem> <SurveyItem ItemNo="6" ItemType="MultipleChoice"> <ItemText>Prefer? </ItemText> <Subitem SubitemNo="1">Normal daytime (8:00-5:00)</Subitem> <Subitem SubitemNo="2">Evening (6:00-9:00)</Subitem> </SurveyItem> p. 2.9
Back to the Internet
Who controls the Internet?
Nobody controls it; it is public, cooperative, and an independent network Several organizations set standards
Internet2 (I2) World Wide Web Consortium (W3C)
Internet-related research and
development project
Oversees research, sets
standards and guidelines
Develops and tests advanced
Internet technologies OASIS
HTTP, HTML, XML Business to Business eCommerce ebXML
Back to Networks
What are network technologies?
token ring Ethernet TCP/IP
Open
Novel
Proprietary
UDP
Format and Protocols are secret to and owned by a company
Standards in public domain
Back to Networks
What is transfer rate?
Speed at which a line carries data and information Faster the transfer rate, the faster you can send and receive data and information Usually expressed as a measure of bits per second
bits per second (bps) kilobits per second (Kbps) megabits per second (Mbps) gigabits per second (Gbps)
Back to Networks
What are some types of network lines?
Back to Networks
What is physical transmission media?
Wire, cable, and other tangible (touchable) materials used to send communications signals
Back to Networks
What is wireless transmission media?
Send communications signals through air or space
Back to Networks
What is Ethernet?
LAN technology that allows computers to contend for access to network Detect collisions an resend (CSMA/CD) Based on bus technology
personal computer personal computer personal computer
personal computer
personal computer
Figure 4.11 Communication over a bus network
Back to Networks
What is token ring?
LAN technology that controls access to network by requiring network devices to share or pass a special signal, called a token Device with token can transmit data over network Only...