A global, public network of computer networks. Computer Network A collection of computing devices connected to share resources such as: Files Software Processors Storage and printers

Internet technology and the physical connections between devices support many applications….. Such as…. and the Web. Provides a convenient and low-cost form of communication over the internet. Web: Provides a convenient method of sharing information and services.

Web = Internet ?? Internet Provides the technological infra-structure on which the Web and other Internet-based services depend. Web Provides a convenient platform for delivering information and services using the Internet Communicating Sharing Learning Finding entertainment Making new friends

Internetwork Networks joined together into larger networks so that users on different networks can communicate and share data’s Intern Today’s Internet joins together networks of over 500 million computers (or Internet hosts) to create the world’s largest internetwork

Pre-Web Internet development milestones 1958 President Eisenhower formed Advanced Research Projects Agency (ARPA) and National Aeronautics and Space Administration (NASA) in response to the USSR launching of Sputnik 1969 ARPA commissioned ARPANET for research into networking. (ARPANET – Advanced Research Projects Agency Network)

Pre-Web Internet development milestones Their initial goal: Establish closer communications for research by connecting the computer networks of four research institutions: University of Calif. At Los Angeles Stanford University of Calif. At Santa Barbara University of Utah Once this goal was accomplished, they grew exponentially.

Pre-Web Internet development milestones 1970 The first cross-country link was installed by AT&T to connect networks across the country ARPANET went international as it expanded overseas to University College in London, England, and the Royal Radar Establishment in Norway ARPANET was divided into two sub-networks: MILNET, for military needs, and ARPANET, for research.

Pre-Web Internet development milestones 1990 The ARPANET project was officially concluded, and “the Internet” was turned over to the public, to be managed by the Internet Society (ISOC) 1991 The Commercial Internet Exchange (CIX) Association was established to allow businesses to connect to the Internet The first Web browser, Mosaic, was released to Internet users to an unprecedented enthusiastic reception.

Digital Divide: The difference between those that have access to the internet and those that don’t. The Internet is a combination of hardware, protocols, and software. Hardware : provides the physical cables and devices that control and carry Internet data. Protocols: the rules that are implemented in network software and hardware to establish connections between two or more computers to allow them to communicate. Software: Allows users to interact with the Internet to access information and services.

Network Service Providers: A company that provides backbone services to an Internet service provider The Internet backbone refers to the principal data routes between large, strategically interconnected networks and core routers in the Internet. It is made up of many national and international communication networks that are owned by major telecom companies such as AT&T and Sprint. These companies agreed to connect their networks so that users on all the networks could share information over the Internet.

Network service providers enable Internet users to connect to their networks through utility stations called “points of presence” (POPs) The POP’s act as the hubs, and the connections they provide, the spokes.

INTERNET Users connect to the Internet through an Internet Service Provider (ISP) Which connects to the network service provider (NSP) through a point of presence (POP) ISPPOPNSP

Accessing the Internet Dial-up Low speed internet service that utilizes the customer’s phone line for data transfer. Rates may go as high as 56 Kb per second Cable Modem High speed internet service provided by cable television service providers. DSL High speed internet service provided through the phone line. Digital Satellite High speed internet service provided through satellite connection.

TCP/IP Transmission Control Protocol/Internet Protocol Policies and procedures for transmitting over the internet. Data Packet Small group of bytes that includes the data being sent and a header containing information about the data, such as…. destination origin size identification number Internet Protocol (IP) The Internet Protocol (IP) defines the format and addressing scheme used for the packets All devices connected to the internet have a unique IP Address IP Address: a unique 32 bit identifier for internet hosts. Static: permanently assigned to a particular computer Dynamic: assigned to computers as needed.

Succeeding with Technology

Domain Names Because people are more comfortable dealing with names than numbers, IP addresses are assigned associated English names called Domain Names Registering a domain name does not provide you with your own Web site, only with ownership You can associate the name with a Web site you have created and stored on a Web server with an assigned IP address Domain Name System (DNS) The Internet uses the DNS to translate domain names into IP addresses. A database of address and names is stored on DNS servers.

Succeeding with Technology TCP/IP provides a standard that is fairly easy to implement, public, free, and extensible The Internet is not owned, operated, or controlled by any single entity TCP/IP is glue that holds the Internet together

Succeeding with Technology The IP part of TCP/IP defines the format for the addresses that identify computers on the Internet These addresses are called IP addresses An IP address is a series of numbers, such as o It is separated into four sections by periods o Each section’s number cannot exceed 255 o Each address requires __ bits (8 bits per section)

Internet Software Two basic architectures: o Client/server  Client makes a service request  Server provides the service  Port  Logical addresses on the server Client/server technology is the basis of Internet services such as and the Web and uses server computers to distribute data to client applications such as Internet Explorer o Peer-to-peer (P2P) networking  F acilitate communications directly between clients

Peer-to-peer Networking Succeeding with Technology

The protocol of the Web is called HTTP Hypertext Transfer Protocol (HTTP) – controls communication between Web clients and servers. A Web client is commonly called a Web Browser. Markup Languages A markup language is used to describe how information is to be displayed. The primary markup language that is used to specify the formatting of a Web page is called Hypertext Markup Language (HTML)