ROANOKE TIMES 
                      Copyright (c) 1996, Roanoke Times

DATE: Monday, January 2, 1996                TAG: 9601030043
SECTION: EXTRA                    PAGE: 3    EDITION: METRO 
COLUMN: At home with technology 
SOURCE: DAVID BUTLER 

ISDN FINALLY TAKES OFF

Q: What ever happened to ISDN, the all-digital network that was supposed to revolutionize telephone service?

A: Because our country's aging telephone network is a patchwork of disparate local and regional mini-networks, ISDN (Integrated Services Digital Network) has been slow in coming.

Much of the telephone network is already digital. The biggest challenge facing ISDN lies in the last few miles of the network - from the local switch to the customer. In many areas, local subscriber loops, as they're called, are either too long (greater than three miles) or contain equipment that's not compatible with the stringent demands of digital signaling.

These issues can be resolved - for a price. Therein lies the problem. Businesses in most medium and large cities have been able to get ISDN and other all-digital lines for years. For the phone company, it boils down to the economics of density.

At last, a dramatic upswing in ISDN deployment is underway - especially in suburban areas. The reasons are revealing: falling equipment prices, incentives or mandates from a growing list of state regulatory agencies, the threat of competition from the cable industry and, perhaps most telling of all, an economy that's increasingly reliant on high-speed information access.

Without getting too technical, here's a brief primer on what promises to be the last ``mile'' of the information highway. Integrated Services Digital Network is designed to operate over existing copper wires that connect homes and businesses to local telephone switches. In a sense, comparing an analog phone line to ISDN is like comparing a vinyl record to a multimedia CD-ROM.

Through digital magic, one ISDN line can support 64 phone numbers and up to eight calls on hold; as many as three can be active at one time. The total data rate, 144 kilobits-per-second (kbps), is about ten times faster than most computer modems. It breaks down like this: two 64-kbps ``B'' (bearer) channels plus one 16-kbps ``D'' (data) channel. This grouping is referred to as a BRI (Basic Rate Interface). In some states, an ISDN line costs as little as $24 a month!

Why all the fuss? With ISDN, background noise is almost nil. You'll REALLY be able to hear a pin drop! Moreover, once you dial a number, it rings almost immediately. Analog connections sometime seem to take forever. During the 30 seconds or so it takes an analog fax machine to set up and begin sending the first page, an ISDN (Group 4) fax machine can transmit nine laser-quality pages! And though ISDN phones are still pricey, they offer some incredible features.

Perhaps the most compelling reason to consider ISDN can be summed up in one word - the Internet. As millions of people have no doubt discovered, surfing the Web requires the patience of Jobe. Now that 64- and 128-kbps ISDN terminal adapters (the digital equivalent to a modem) are entering the market in force, Internet access providers are scrambling to offer ISDN connections.

Both internal and external terminal adapters are now available for as little as $300. Although an external adapter is limited by the computer's serial port (typically 115 kbps), it offers more flexibility. External adapters often include an extra ISDN port as well as an analog phone jack. Some models are capable of communicating with an analog modem. These are often referred to as "digital modems."

Most regional phone companies have set up ISDN support centers to answer questions. Even though ISDN is a standard, getting a specific telephone or adapter to work can take some effort. To alleviate setup problems, many products now include "ordering codes" to help phone company technicians configure the line. Once everything's working, it should stay that way. After all, it's digital!

To receive a list of companies that manufacture ISDN telephones, terminal adapters and digital modems, please send $1.50 and a self-addressed envelope to David Butler F-545, Department TNW, 14713 Pleasant Hill Road, Charlotte, N.C. 28278-7927. The list includes toll-free phone numbers and a summary of each company's products. You'll also receive phone numbers for regional ISDN support centers.

LENGTH: Medium:   79 lines
ILLUSTRATION: GRAPHIC:  In some states, an ISDN telephone line costs as little
          as $24 per month. With the proper adapter, ISDN supports both analog
          and digital products.