ADTRAN Announces Interoperability with ADC HDSL2 Systems; Leading System Vendors Team Up to Ensure Interoperable Deployments.

Business Editors/Technology Writers

HUNTSVILLE, Ala.--(BUSINESS WIRE)--April 4, 2000

ADTRAN, Inc. (NASDAQ:ADTN)(www.adtran.com), a market leader in DSL deployment equipment and ADC (NASDAQ:ADCT)(www.adc.com), a leading global supplier of network equipment, software, and integration services, announced today that they have demonstrated interoperability of their independently developed HDSL2 system solutions. Both companies contributed to the development of the ANSI T1.418-2000 HDSL2 standard, and continue to promote interoperability through their participation in multivendor interoperability testing.

"ADTRAN is firmly committed to the HDSL2 standard and is aggressively pursuing interoperability with leading equipment manufacturers like ADC," said Tom Stanton, VP and General Manager of ADTRAN's Carrier Networks Division. "Interoperability among vendors encourages healthy competition resulting in higher quality products, lower prices, and better service."

"ADC and ADTRAN are among the first to demonstrate that products adhering carefully to the HDSL2 standard will be fully interoperable. This is good news for service providers and the vendors who support them," said Sean Martin, VP of Marketing and Product Management for ADC.

Both ADTRAN and ADC will continue industry-wide interoperability testing, both independently and through the industry-sponsored HDSL2 Consortium at the University of New Hampshire InterOperability Laboratory.

About ADTRAN

Established in 1985, ADTRAN, Inc. is a leading provider of network deployment and access solutions for delivering today's digital telecommunications services over existing copper infrastructures.

Today, ADTRAN technologies support more than two million local loops worldwide. More than 500 ADTRAN products support all major digital technologies, including T3, T1, E1, Frame Relay, DDS, HDSL, HDSL2, SDSL, xDSL, ISDN, and wireless transport. In the carrier network and enterprise markets, ADTRAN produces a complete end-to-end solution that provides the greatest network efficiency and lowest possible telecommunications costs.

According to Dataquest and IDC, ADTRAN holds revenue-leading positions in the Frame Relay/DDS, ISDN Extension and HDSL/T1/E1 network and access markets. ADTRAN customers include the Regional Bell Operating Companies, interexchange carriers, GTE, domestic independent service providers, corporate end users, international customers and original equipment manufacturers.

For more information, contact the company at 800/9ADTRAN (800/923-8726), 256/963-8000, or via e-mail at [e-mail]. On the web, visit http://www.adtran.com.

About ADC

ADC Telecommunications, Inc. is a leading global supplier of network equipment, software and integration services for broadband, multiservice networks that deliver data, video and voice communications over telephone, cable television, Internet, broadcast, wireless and enterprise networks. ADC's broadband, multiservice network solutions enable local access, high-speed transmission and software management of communications services from service providers to consumers and businesses over fiber-optic, copper, coaxial and wireless media. Headquartered in Minneapolis, Minnesota, ADC has approximately 14,400 employees around the world and annual sales of $2.1 billion. ADC's stock is included in the Standard and Poor's 500 Index and the Nasdaq-100 Index. For additional information, visit our Web site at www.adc.com.