RICHARDSON, Texas, June 8, 1999 - Fujitsu Network Communications, Inc., announced today that Allegiance Telecom, Inc., is outfitting its New York and Dallas networks with Fujitsu transmission equipment to provide reliable voice, data, and Internet services. Allegiance Telecom (NASDAQ: ALGX) is using the Fujitsu family of fiber-optic multiplexing equipment and the Metro version of Fujitsu's FLASHWAVEª wave division multiplexing (WDM) system.

To provide its services, Allegiance Telecom deploys multiple Synchronous Optical Network (SONET) rings, which use fiber-optic cable to connect the Fujitsu equipment at various locations. SONET rings are designed for extremely reliable high-speed transmission over fiber-optic cable. They can route signals to their destination even if one of the fibers in the network is cut or damaged. Fujitsu's equipment raises network performance to the highest standards, so that customer traffic reaches its destination without interruptions.

"Reliability was a key reason for selecting Fujitsu as our supplier," said John Pena, vice president of engineering for Allegiance Telecom. "Fujitsu's SONET multiplexers enable us to provide high-quality service to our customers in a truly survivable environment."

Allegiance Telecom offers services in 14 major cities throughout the country: Atlanta, Boston, Chicago, Dallas, Fort Worth, Houston, Los Angeles, Northern New Jersey, New York, Philadelphia, Oakland, San Francisco, San Jose, and Washington, D.C.

Fujitsu's SONET-based family of multiplexers include the FLM 150, FLM 600, and FLM 2400 add/drop multiplexers (ADMs), offering transmission capacities up to 2.5 gigabits per second - the equivalent of more than 32,000 simultaneous telephone calls - over a single fiber.

Allegiance Telecom is taking advantage of the FLM 150 ADM's transmux capability, which provides the ability to accept DS1 (1.544 megabits per second) inputs at one or more points in the network and hand off a combined DS3 (45 Mbps) signal at a hub location. With transmux, internal M13 multiplexing eliminates the need for asynchronous M13 multiplexers, providing equipment, maintenance, and operations savings. Transmux functionality is ideal for access networks and point of presence locations.

Allegiance Telecom has also deployed multiple nodes of Fujitsu's FLASHWAVE Metro system, which supports up to 8 channels of OC-48 (2.5 gigabits per second) transmission for a maximum capacity of 20 gigabits per second. The modular design of the FLASHWAVE system allows channels to be added as needed.

"The FLASHWAVE system provides the capacity to support our backbone network," said Pena. "What convinced us to purchase Fujitsu's system is the fact that it allows us to start with as many channels as we want and provides the flexibility that is necessary for our network's growth."

"The FLASHWAVE system was the logical choice for Allegiance Telecom," said Ron Martin, executive vice president of planning and development for Fujitsu Network Communications. "It is an incredibly scalable system, which enables Allegiance Telecom to grow the system as its customers' bandwidth demands increase. We are delighted to be chosen as Allegiance Telecom's SONET and WDM supplier."

Allegiance Telecom (www.allegiancetele.com) is a facilities-based local exchange carrier headquartered in Dallas, Texas. Allegiance offers businesses a complete package of telecommunications services, including local, long distance, international calling, high-speed data transmission and Internet services. Allegiance is targeting 24 major metropolitan areas in the U.S. with its "one-stop shopping" approach. Allegiance's common stock is traded on the Nasdaq National Market under the symbol ALGX.

Fujitsu Network Communications, Inc., designs and manufactures fiber-optic transmission and broadband switching platforms, develops software that allows customers to perform in-service management and monitoring of the network, and provides network design, installation, and maintenance services. Its customers include local exchange carriers, interexchange carriers, competitive access providers, and cable TV operators, as well as large private networks in North America. Fujitsu Network Communications is part of Fujitsu Limited (TSE: 6702), a $43.3 billion leading provider of comprehensive information technology and networking solutions for the global marketplace. Product information is available by calling 800-777-FAST. Its World Wide Web site is www.fnc.fujitsu.com.