Getting Online, Working Online

section 8b

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

• Non-Standard Methods

• Common Connection Methods

• High-Speed Data Links

Accessing the Internet

• 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 that converts comments and data to and from TCP/IP format.

These methods of connecting to the Internet are not commonly used:

Accessing the Internet - Non-Standard Methods

• 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.

Here are some very common methods for connecting PCs to the Internet:

Accessing the Internet - Common Connection Methods

• ISDN service can transmit data up to 128 Kbps and carries voice and data signals over a single connection.•ISDN services operates on standard telephone lines but requires a special model and phone service.

• 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.

Because modem speeds are limited to 56 Kbps, many home users and small businesses connect to the Internet via high-speed lines, such as:

Accessing the Internet - High-Speed Data Links

xDSL Services (Option)

很多 ISDN數據機利用資料壓縮技術讓一條 ISDN線的資料傳輸速度增加一倍

DSL連接在那些需要提供網際網路存取給多位使用者的小型企業

Cable Modem在可和標準 ISP帳號相比的花費情況下提供快速的資料傳送速度

• Connect a computer to the Internet involves two separate issues: software and the network connection.

• 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.

Connecting a PC to the Internet

• Many companies offer suite of Internet access tools•E-mail, Telnet, FTP, browser…

• This all-in-one approach has several advantages•The applications in a suite share a common interface design

•There is a single point of contact for technical support and product upgrades

•No incompatibilities between software and the network if a suite also include an account with a particular ISP.

Connecting a PC to the Internet (Cont.)

• Businesses and Firewalls

• Intranets and Extranets

• Issues for Telecommuters

Working on the Internet

• 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.•By inspecting the requests and data that passed

• A firewall gives outsiders access to public areas of a network while restricting access to protected parts of the network.

Working on the Internet - Businesses and Firewalls

STOP

Invalidpassword

• 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. If it is connected to the Internet, then it is secured by a firewall.

• 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 - Intranets and Extranets

• 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.

Working on the Internet -Issues for Telecommuters

• The Web is a vehicle for electronic commerce(e-commerce), which simply means doing business online.

• You can pay in the e-commerce in several ways.•One-Time Credit Card Purchase: Use the credit card to purchase•Set Up an Online Account:

•Set up an account at the Web site•Then vendor then stores your personal information on a secure server and a special file (called a cookie) on your computer’s disk.

•Use Electronic Cash•Use an Electronic Wallet:

•an electronic wallet is a program on your computer that stores credit card information, a digital certificate that verifies your identity and shipping information.•A different version, called a thin wallet, stores the information on a server owned by your credit card company

Commerce on the World Wide Web

• Security: use a secure Web page

• Two ways to identify a secure Web page•Check the URL: https:// or ends with shtml

•Check your browser’s status bar: a small padlock symbol will appear in the browser’s status bar (Fig. 20.10)

• Two ways to provide secure Web page•Secure socket layer (SSL): encrypt data•Secure HTTP (S-HTTP) protocol•SSL can encode any amount of data, S-HTTP is used to encode individual pieces of data.

Commerce on the World Wide Web (Cont.)

• Security: use a secure Web page

• Two ways to identify a secure Web page•Check the URL: https:// or ends with shtml

•Check your browser’s status bar: a small padlock symbol will appear in the browser’s status bar (Fig. 20.10)

• Two ways to provide secure Web page•Secure socket layer (SSL): encrypt data•Secure HTTP (S-HTTP) protocol•SSL can encode any amount of data, S-HTTP is used to encode individual pieces of data.

Commerce on the World Wide Web (Cont.)

安全的網頁

• 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.

Commerce on the World Wide Web (Cont.)

像很多其他的電子商務網站以消費者為對象， amazon.com提供瀏覽，大規模輔助系統、安全購物和其他特色

• 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.

Section 8b review