By Les Freed and Frank J. Derfler, Jr
PC Magazine

April 22, 1999

1 Does your PC already have an Ethernet card? The service may ask you to pay for another Ethernet adapter even if you already have one.

2 If you don't already have an Ethernet card, do you have a free PCI expansion slot? Cable, DSL, and satellite connections commonly use a PCI card.

3 Do you have USB in the computer and a USB-compatible operating system? USB-equipped cable modem, DSL, and satellite devices are just emerging. If you use USB, you don't have to open the PC.

4 Do you want to use a special service such as AOL? Some access schemes require a significant work-around to use AOL or other proprietary service providers.

5 Do you already have a local area network? Many cable modem and DSL installations will disable an existing LAN connection.

6 For cable modem: If you already have cable television, where does the cable come into the building and how is it distributed? You should try to eliminate splitters not installed by the cable company. Cable TV distribution amplifiers, often found in apartment buildings, can cause problems.

7 For cable modem: Is a cable outlet convenient to your computer?

8 For DSL: How is your telephone wiring distributed? You can incur significant charges for changing inside wiring.

9 For satellite: Do you have a clear view of the southern sky at an angle of about 45 degrees up from the horizon? The antenna can sit on the ground or on a roof, as long as it can see a specific patch of sky.

10 For satellite: How can the installer bring in a cable from the antenna and reach your computer?

Glossary of Communications Terms

Central office (CO) A telephone company facility that serves a specific geographic area. All phone lines run from a subscriber's home or office to a CO.

CLEC (Competitive Local Exchange Carrier) A phone company that competes with the primary local exchange carrier (ILEC) in a given market. A company may be the ILEC in one market and CLEC in another.

Data Over Cable Service Interface Specification (DOCSIS) A relatively new industry standard defining how cable modems communicate over cable TV lines. Any DOCSIS modem will work on any DOCSIS-compatible cable TV network.

Digital subscriber line (DSL) A communications technology that provides high-speed, two-way data communications over existing analog phone lines. DSL doesn't interfere with the existing phone service on the line, so you can still use your phone to place and receive calls at all times. There are several varieties of DSL, but the most widely deployed is ADSL (asymmetric DSL), which provides downstream speeds of 500 Kbps to 8.1 Mbps and upstream channels from 100 to 200 Kbps, depending on the user's distance from the phone company central office.

G.Lite An ITU standard for DSL technology that delivers download throughput of up to 1.5 Mbps. G.Lite is expected to become the main standard for residential and small-business DSL service.

Headend The cable TV equivalent of a phone company central office, the headend is the cable company's main signal reception and distribution facility. All TV cables for a given city route back to a single headend.

Incumbent Local Exchange Carrier (ILEC) The primary local phone service provider for a given market. Also called an RBOC (Regional Bell Operating Company).

ISDN (Integrated Services Digital Network) An all-digital replacement for analog telephone service. ISDN provides two 64-Kbps channels, which can be used together or independently to carry voice or data.

Virtual private network (VPN) An authentication, encryption, and data-packaging technology that allows private network traffic to travel over the public Internet. VPNs provide remote-office and work-at-home users with secure access to a corporate LAN or WAN. VPN traffic is encrypted so that it cannot be deciphered as it travels over the Internet.

Editors' Hot Links

www.pcmag.com/hotlinks
There's no more comprehensive Internet coverage online than PC Magazine's. For a comprehensive guide to DSL and cable modem services by state, go to the URL above.

International Telecommunications Union [ http://www.itu.int/ ]
Based in Geneva, Switzerland, the ITU approves the standards for the telecommunications industry. The ITU site has some good papers and speeches on the global telecommunications industry.

CableModemInfo.Com [ http://www.cablemodeminfo.com/ ]
An excellent source for cable- and DSL-related links. It includes links to manufacturers of cable-modem-related software, including proxy servers.

Security Considerations for Residential Broadband Access Services [ http://www.inetdevgrp.org/19980721/ppframe.htm ]
A good site covering DSL and cable modem generalities, with an emphasis on security and multiple connections in a residence.

Cable Modem University [ http://www.catv.org/modem ]
This is a great site for nitty-gritty technology information, market research on the cable industry, and information on the availability of cable modem service.

Cable Modem Resources on the Web [ http://rpcp.mit.edu/~gingold/cable ]
This MIT-sponsored site has lots of cable-related links, including cable modem manufacturers, periodicals, and testing sites.

ADSL Forum [ http://www.adsl.com/ ]
Information on upcoming ADSL conventions. This site is also an excellent repository of information on everything DSL, including current service availability.

Universal ADSL Working Group [ http://www.uawg.com/ ]
The UAWG has been working toward a universal ADSL modem standard. Go to this site to find out more about G.lite.

Copyright 1999