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Networks and Internet

Objectives Understand basic concepts in NetworkingNetwork Types Understand basic concepts in InternetInternet ServicesBecome familiar with Web terminologies

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Computer Networks

Physical part of the definition:–Two or more computers linked together.

Functional Part of the definition:

–Communication

–Sharing resources

–Exchange of data

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Computer Networks

Types of Networks Local Area Network (LAN) – nodes are in close proximityWide Area Network (WAN) – nodes of the network are geographically distantInternet – Network of networks and individual computers

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Going Online

The Internet Internet: worldwide collection of networks ARPANET: network for scientists that evolved into the Internet Internet backbone: major communications lines of the Internet

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Going Online

The InternetNo one group controls the Internet Three Major Organizations:

The Internet Society: Open development for the benefit of the public Internet Corporation for Assigned Names and Numbers (ICANN): Assign names and addresses World Wide Web Consortium (W3C): Creates technical specifications

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Going Online

Connecting to the Internet Bandwidth – amount of information that can be sent over the channel

56,000 bits per second (bps)9M (millions of bits, or megabits per second)

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Going Online

Connecting to the Internet Internet service provider (ISP): Colleges, Schools, Corporations, Communication companies ex. SBC Information service gateway: ex. AOL, MSN, CompuServe

communications software (Interface with their information system) user ID and password

Direct LAN connection T-1 line (1.544 Mbps) T-3 line (44.736 Mbps)

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Going Online

Connecting to the Internet Transmission Control Protocol/Internet Protocol (TCP/IP)

Protocol: set of rules for how computers communicate Packet: the part of a message that contains the data and the address the message is being sent to

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Going Online

Retrieving and Viewing Information on the Internet

Client program – Internet browser: runs on user’s computer Server program – runs on server computer

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Going Online

Retrieving and Viewing Information on the Internet

Domain name: name or abbreviation of the name of the organization Uniform resource locator (URL): address of a web page

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Going Online

Retrieving and Viewing Information on the Internet

URL access protocol domain name

top-level domains: denote affiliation.com .edu

folder filename

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Going Online

Internet Browsers Browsers

retrieve and view Internet-based information interact with servers download and upload information

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Going Online

Internet Browsers Web site pages home page – first page you see at a site hyperlinks – allow user to click on an icon and be taken to other resources on the Internet

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Going Online

Navigating the Internet Microsoft Internet Explorer Netscape

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Going Online

Browser Plug-ins Plug-in – gives the browser added capabilities

Shockwave Player Flash Player RealJukebox Liquid Player

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Going Online

Internet Resources and Applications Finding information on the Web

browsing: just looking around searching: trying to find specific information

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Going Online

Internet Applications File Transfer Protocol (FTP) servers

easily download/upload files

Anonymous FTP sitesE-mailChattingOnline conferences

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Assignment# 3