The Internet

Taken from

The Internet Complete Reference, Second Edition, Hahn

Chapters 1 - 6


Chapter 1: Introduction

What is the Internet?

Network: two or more computers connected together.



Chapter 2: Understanding the Internet

Our Friend The Network

LAN (Local Area Network)

WAN (Wide Area Network)

Backbone: High-speed (usually fiber optic) link which connects WAN's and LAN's.

Router: A computer which connects one LAN or WAN to another LAN or WAN.

The Internet strongly relies on the telephone system.

The Secret of the Internet: Clients and Servers

Servers: Programs provide resources

Clients: Programs that are used to access those resources.

The Internet allows Clients programs to talk to Servers programs.

X Window and X Clients

X Window is a common GUI that works on all types of Unix.

Hosts and Terminals

Host has two meanings

Terminal: A keyboard and monitor attached to a Host at some other location.

Timesharing System: More than one user shares a computers resources from different terminals.

What Is TCP/IP

Protocols: A set of rules which technically describe how something should be done.

Data is broken up into manageable sized packets in order to travel over a network.

Packet Header: Information regarding the contents of the packet. Includes destination of packet, point of origin, packet sequence number, size, error checking information.


To see packets in action try the ping command.

ping Lets you know if Northern Illinois University's system is responding.
Ping -s Repeats ping and lets you know haw fast your packets are getting to Norther Illinois University. Use Ctrl-C to quit.
ping -sRv Repeats ping and tells you the route the packets take to get to NIU. Ctrl-C to quit.


Chapter 3: A Tour of the Internet

Mail: Electronic Mail allows us to communicate over the Net and share files of all types.

The Web: A large system of servers which offers all kinds of information to users on the Net via client programs - Web browsers.

Web Search Engines: Tools that keep track of web sites around the world and let you search for particular items whenever you want.

Usenet: A system of discussion groups in which individual articles are distributed throughout the world.

Gopher: A system similar to the Web, in that you use a client to connect to servers all over the world in order to access information. Gopher presents the information through a series of menus. Menu items, once selected, may bring up information from the current server or connect the user to a menuing system on a different system.

Veronica and Jughead: Search Engines designed for use on Gopher sites.

FTP (File Transfer Protocol): Allows you to copy files from one computer to another.

Archie: A search engine designed for finding files on Anonymous FTP servers.

Mailing Lists: An organized system in which a group of people are sent messages pertaining to a certain topic from fellow members of the group.

Telnet (Remote Connection): A service allowing you to log in and use a remote computer via a telnet client.

Talk Facilities: Allow you to communicate with other people on the Net in real time, either by typing messages back and forth or by actual voice conversation.

Internet Relay Chat (IRC): A public talk facility which can be used by anyone on the Net at any time.

MUDS, MUCHs, MOOs, MUSEs, MUCKs: Virtual Reality IRCs. Use graphics to place the players/participants in an imaginary setting of some type. Users can choose an Avatar to represent their presence in the imaginary setting.


Chapter 4: Hardware Requirements to Connect to the Internet

What do you need to use the Internet?


Accessing the Internet via Your Local Network

Accessing the Internet is easy from campus. Since FSU is already connected to the Internet, all you need to do is log on to your FSU account from any of the hundreds of FSU computers.


Accessing the Internet via the Telephone System

Here's what you need:


Choosing a Computer

Don't be cheap. Look to spend between $1,500 and $2,500.


Choosing a Modem

External or Internal?

56Kbps is tops!



ISDN (Integrated Services Digital Network)

High speed (64 - 128 Kbps) connection offered by the phone company.

64 Kbps if sharing the line with a telephone.

128 Kbps if using only for computing.

Digital connection rather than analog.

Basic Rate Interface (BRI) recommended for home use.

Primary Rate Interface (PRI) recommended for large businesses.


What do you need in order to use ISDN?


Other methods of connecting

Cable modems

ADSL (Asymetric Digital Subscriber Line)


For more on connective hardware:


Chapter 5: Software Requirements and Internet Service Providers

Hosts and Terminals

Two types of Internet connections from home:

Preferably, you want a service that provides both of the above - like FSU.


Unix Hosts, VT-100 Terminals, and Telnet

With shell accounts and telnet client programs your home PC emulates a VT-100 terminal when connecting to a Unix server.


Shell Accounts


PPP Accounts



SLIP (Serial Line Internet Protocol) does what PPP does but not as well. PPP took over for SLIP.


Internet Service Providers (ISP's)

Tallahassee Freenet

Tallahassee Internet Service Providers

America Online, Compuserve, Prodigy, etc


Choosing an Internet Service Provider

Some important questions:


What software do you need?

For a PPP account, you need TCP/IP, PPP and Internet clients.

For a shell account you only need a communications program.

Windows 95, Windows NT 4.0, & OS/2 Warp, and Mac System 7.5 or later all come with TCP/IP and PPP software.

Earlier versions of Windows will require a Winsock (Windows socket interface) program such as Trumpet Winsock.

Earlier versions of MacOS will require MacTCP.

A great source for free downloadable Internet programs and clients is


Installing and Configuring TCP and PPP

Things you'll need to know:

Setup can be confusing the first time. ACNS has very good documentation to follow. It helps tremendously to have an experienced user around to help.


Where to get Internet client programs

On line! Try


Chapter 6: Internet Addressing


Basic format:


Email addresses are case insensitive. Upper case or lowercase makes no difference.

Here the router would look for a local computer named misty.

Top-level domains:

.com Commercial organization
.edu Educational organization
.gov Government
.int International organization
.mil Military
.net Networking organization
.org Non-profit organization


Geographical top-level domains are used for some non-US countries (see Figure 6-2).

Some smaller companies have larger organizations serve as their email gateway (which can be misleading).


IP Addresses and DNS

When InterNIC agrees to register your network on the Internet, you are given an Internet domain name ( and an Internet IP address (

Domain Name Servers (DNS) have the responsibility of translating Internet domain names into IP addresses.

For more on registering your domain name see

Use the host command to translate domain names to IP addresses and IP addresses to domain names.


will give you our IP address.


Other Networking Systems that use Unique Addressing

UUCP: Connects Unix computers. Comes free with Unix OS.

Fidonet: Worldwide network of PC's connected via telephone lines.

Bitnet: Collection of different networks based in US, Canada, Mexico and Europe.


The End J