Chapter 2: ISDN Helps People Work Together

ISDN For Network Overflow

The worldwide dedicated voice and data networks of many corporations are critical to the orderly, day-to-day conduct of business. A failed connection can often shut down a firm's ability to carry on its business.

For protection, many firms have traditionally maintained two separate networks - one as primary, the second as a backup. Today, however, many organizations find that ISDN lines offer a better alternative: excellent backup and overflow capabilities for either a voice or data network - at a fraction of the cost. Some typical examples include:

Avis Rent A Car. The global rent-a-car giant, headquartered in Garden City, Long Island, chose ISDN to back up its critical worldwide reservations and information system. With operations in 140 countries, the Avis "Wizard" system is today online to 33 nations, with new countries added frequently.

The Avis network primarily handles online automobile rental reservations, with an average worldwide response time of about two seconds. It also carries sales orders and reporting, billing data, company-wide e-mail, file transfers and more. The ISDN backup system is currently deployed in eight countries including the U.S., and is designed to establish dialed 128Kbps connections in less than three seconds after a network failure occurs.














William Morris Agency. ISDN back-up capabilities are also in place for this talent agency's worldwide leased-line network, linking offices in New York, Nashville, Beverly Hills and London. The system lets agents in each office share and access information about clients and bookings.

"We use leased lines for our permanent connections in the United States," said Mike Clark, the firm's network manager, "but we rely on ISDN for backup and overflow of these critical network connections. Dialed ISDN links are also our primary connections to London."

Little, Brown and Company. The worldwide publishing firm headquartered in Boston backs up four dedicated T1 connections using ISDN. "We back up only the data channels, ranging from 56 to 128Kbps lines," says Frank Chiacchieri, the company's director of microcomputers. Intelligent Adtran DataProbe switches monitor each channel and automatically dial 128Kbps backup connections within seconds." Chiacchieri adds that in several self-inflicted failures, the system has performed flawlessly.

Baystate Health Systems. Baystate Health Systems in Springfield, MA, also protects key elements of its regional backbone network with Gandalf bridges, yet has this same equipment ready to assume a much larger backup role.

"We keep a complete system backup offsite," says Michael Weisse, senior systems programmer at the center, "with data records backed up every day." In the event of a disaster in the computer room - a fire or flood for example - a complete copy of the facility's records would be delivered to Business Recovery Systems in Sterling Forest, NY. "They maintain a physical duplicate of our system," Weisse notes, "and we would use dialed ISDN connections to access and use that system. We've tested the set-up, and it works quite well."