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.