I-C. Hardware Requirements and Options

1. Terminal - A device that allows you to send commands to a computer somewhere else (in the next office cubicle, across town, or in another country) and to receive data from that computer.  At a minimum, this usually means a keyboard and a display screen and some simple circuitry.  Usually you will use terminal software in a personal computer (See Session I.D. below) in which case the software pretends to be ("emulates") a physical terminal and allows you to communicate with a computer somewhere else.

2. Access - Typically, until recently, via an Analog Modem (MOdulator, DEModulator) - a device that you connect to your computer and to a phone line or other connection that allows the computer to communicate with other computers.  Basically, modems do for computers what a telephone does for humans.  Recently, additional access options have become available:

Access Option	28.8/56.6 Analog Modem	DSL	Cable	Satellite
Theoretical Upload/Download Speed	56.6Kbps	144Kbps to 1.7Mbps/ 144Kbps to 8Mbps	33.6Kbps to 4Mbps/ 384 Kbps to 4Mbps	33.6Kbps (via analog modem)/ 400 Kbps
Typical Upload/Download Speed	19.0Kbps/ 50.0Kbps	Depends on service type and distance from central phone office	Depends on remote server and its connection to the Net as well as the number of local users sharing the cable line	33.6Kbps (via analog modem)/ around 250Kbps
Possible Ways to Improve Speed	Make sure the modem and ISP are V.90 compliant, do transfer-intensive work early in the morning	Requires a superclean phone line so have yours checked by the phone company and replace wiring if necessary	Cut the neighbors' cable connections (I'm only kidding)	Configure your browser to allow eight simultaneous connections
Setup Costs	Cost of Modem	Up to $50 for DSL modem	Up to $50 for cable modem	$300 to $800 plus modem
Average Monthly Costs	$10 to $20 plus monthly phone service	$30 to $400 depending on service type	$40 to $50	$30 to $130 plus monthly telephone service
Pros	Uses standard equipment, universally available, cheap and easy to set up	Uses existing phone line, always on, blazing speed	Becoming widely available, always on, excellent value	Provides fast surfing, almost universal availability
Cons	The slowest of all services	Not yet commonly available, complex setup, requires that you live within 20,000 feet (3.6 miles) of central office	Slow uploads, requires that you have cable TV, doesn't give you a choice of ISPs	Slow uploads, expensive, requires clear line of sight to the Southwest plus outside antenna and modem for uploads
Who Should Choose It?	Casual Web surfers and anyone who rarely uploads or downloads large files	Anyone who can afford it and has it available	Dedicated surfers who want fast downloads (upload speed depends on provider)	Dedicated surfers who lack access to other fast Internet connections and who rarely send large files

3. Port (COM or Serial) - This is the place where information goes into or out of a computer, for example, the place where a modem would be connected.

4. Packet Switcher - The method used to move data round on the telephone network.  In packet switching, all the data coming out of a machine, either the terminal or the host computer, is broken up into chunks, each chunk has the address of where it came from and where it is going.  This enables chunks of data from many different sources to co-mingle on the same telephone lines, and to be sorted and directed by different routes by special devices along the way.  As a result of packet switching, many people can communicate on the same telephone lines at the same time.

To see how a particular uploaded message travels from your computer to a location on the Internet,

1. Open the Run command on the Start Menu
2. Type TRACERT followed by the Internet address (e.g. www.geocities.com) and press ENTER. (TRACERT stands for Trace Route and is a small computer program stored on your hard drive as part of the Windows installation.)
3. The DOS box on your screen will display the various routings of the message starting at your location and ending at the destination you have chosen

5. Internet Service Provider - On the Internet, packet switching is handled by an ISP (Internet Service Provider), a company that provides access to the Internet. There are three types of ISPs:

1. National ISPs such as AT&T Worldnet and Concentric.Net which provide local calling number access anywhere in the US. (Great for those of us who spend part of the year in Florida, for example)
2. Regional or Local ISPs such as Nerc.com, Erols.com and Comcast.net which provide local calling number access only in the regions they serve, but often offer discounts or additional services not available from the national ISPs.
3. Value-added ISPs such as America Online (AOL), Compuserve, and Prodigy which provide proprietary information content as well as Internet access.

5. Host Computer (or Server) - Any computer that can function as either the beginning or end point of data transfers.  When you are uploading (sending or transmitting) data, you are sending it to a remote host computer.  When you are downloading (receiving) data, your computer is the host. As we shall see, an internet host computer has a unique internet address (IP address) and a unique domain name.  It is usually called a Server because of the function it plays in "serving up" a file containing information in a form that can be transmitted over the Internet on the World Wide Web.