Transcript N4Less20
lesson 20 Getting Online, Working Online This lesson includes the following sections: • Accessing the Internet • Connecting a PC to the Internet • Working on the Internet • Commerce on the World Wide Web Accessing the Internet • Non-Standard Methods • Common Connection Methods • High-Speed Data Links Accessing the Internet Non-Standard Methods These methods of connecting to the Internet are not commonly used: • Direct connection – connects an isolated PC directly to the Internet backbone via serial line interface protocol (SLIP) or point-to-point protocol (PPP). • Remote terminal connection – allows the user to exchange commands and data in ASCII text format with a UNIX host computer. • Gateway connection – connects a non-TCP/IP network to the Internet via a gateway. Accessing the Internet Common Connection Methods Here are some very common methods for connecting PCs to the Internet: • Connection through a LAN – if a LAN uses TCP/IP, it can exchange data over the Internet without a gateway. If the LAN is connected to the Internet via a router, the connection is extended to all nodes on the network. • Connection through a modem – if a stand-alone PC has access to a modem and phone line, it can connect directly or via an Internet Service Provider (ISP). ISP accounts are the most common type of connection. Accessing the Internet High-Speed Data Links Because modem speeds are limited to 56 Kbps, many home users and small businesses connect to the Internet via high-speed lines, such as: • ISDN service can transmit data up to 128 Kbps and carries voice and data signals over a single connection. • xDSL services are available in several forms with download speeds up to 52 Mbps, and also offer simultaneous voice and data transmissions. • Cable modem service offers high-speed data transmission over a cable television system's existing coaxial lines. Connecting a PC to the Internet • To connect a PC to the Internet, you use applications and network connections that conform to the Winsock standard. • The Winsock standard ensures that connections and applications use TCP/IP protocols and can communicate with each other. • You can mix and match any Winsock application and connection and be sure they will work together. Working on the Internet • Businesses and Firewalls • Intranets and Extranets • Issues for Telecommuters Working on the Internet Businesses and Firewalls • Many businesses connect their LANs to the Internet, making their data vulnerable to access by unauthorized users, such as hackers. • Businesses can use a firewall to control access to their network from the Internet, by persons outside the company. • A firewall gives outsiders access to public areas of a network while restricting access to protected parts of the network. Invalid password STOP Working on the Internet Intranets and Extranets • Many organizations are configuring their internal networks to resemble the World Wide Web, so users can navigate them with a browser. • An intranet is a LAN or WAN that uses TCP/IP but is accessible only to internal users. Intranets are not connected to the Internet. • An extranet is an intranet that allows outside access via the Internet. Usually, external users must log in with an ID and password. Working on the Internet Issues for Telecommuters • A telecommuter is someone who works outside the workplace, but uses a computer and communications software to access the company's network, usually over the Internet. • When accessing a corporate network online, telecommuters need to be aware of issues such as security, ownership of sensitive data, libel, and appropriate use of business resources. Commerce on the World Wide Web • The Web is a vehicle for electronic commerce (e-commerce), which simply means doing business online. • For consumers, e-commerce means being able to securely shop, pay bills, and conduct other types of transactions online. • For businesses, e-commerce means a new way to sell and distribute goods and services, and to expand markets beyond physical locations or geographical boundaries. lesson 20 review • Describe how to connect a computer to the Internet. • Identify three kinds of high-speed data links commonly used to connect to the Internet. • Describe the process of connecting a PC to the Internet through an ISP account. • Explain what a firewall is, and the uses for a firewall. • Define the terms intranet and extranet. • Explain what is meant by e-commerce and how it affects consumers and businesses.