ADTRAN and GlobeSpan Announce First Fully Successful Interoperability of Independently Developed HDSL2 Products; Technology Leaders Partner to Ensure Interoperable HDSL2 Deployments.

Business Editors & Technology Writers

HUNTSVILLE, Ala.--(BUSINESS WIRE)--Jan. 18, 2000

ADTRAN, Inc. (Nasdaq:ADTN), the market leader in DSL deployment equipment and GlobeSpan, Inc. (Nasdaq:GSPN), the leading worldwide developer of programmable Digital Subscriber Line (DSL) chipsets, announced today that they are the first to achieve full interoperability of two independently developed HDSL2 solutions through extensive testing using real-world scenarios. Both ADTRAN's and GlobeSpan's participation in the development of the ANSI T1.418-2000 HDSL2 standard, and their commitment to its success, resulted in the achievement of interoperability between the two companies' standards-compliant implementations.

"We were not surprised to find that our HDSL2 products are fully interoperable with products from GlobeSpan, who also adheres to the proposed ANSI standard," said Kevin Schneider, VP of Technology at ADTRAN. "Our success is based largely on the fact that ADTRAN pioneered the technology behind HDSL2, and that ADTRAN authored much of the standard. Because of this level of knowledge of both the standard and the technology behind it, along with the cooperation between ADTRAN and GlobeSpan, we have achieved a level of interoperability that allows us to not only pass data, but to achieve a high level of performance as well."

"GlobeSpan and ADTRAN have set the stage for HDSL2 interoperability at the chipset and system levels throughout the industry," said John O'Neill, GlobeSpan's Symmetric Product Line Manager. "The success of the interoperability tests with ADTRAN reaffirms the advantage in time to market that our programmable architecture provides. GlobeSpan is ready to supply HDSL2 chipsets to equipment suppliers, enabling them to market interoperable products that are compliant with the standard. Interoperability is the baseline requirement that will accelerate the deployment of HDSL2 products, which use only one telephone line to provide T1 data-rate services."

ADTRAN's experience with HDSL2 began with the development of its patented Total Reach(R) technology, which uses TC-PAM (Trellis Coded Pulse Amplitude Modulation) to extend the reach of traditional transmission methods. TC PAM and ADTRAN's POET (Partially Overlapped Echo-cancelled Transmission) form the basis for HDSL2 line code. ADTRAN has played a key role in the development of the HDSL2 standard (ANSI T1.418-2000) by the T1E1.4 working group of ANSI accredited Standards Committee T1-Telecommunications.

GlobeSpan's HDSL2 product development is rooted in more than seven years of DSL field-deployment experience with complex coded DSL systems, as well as high-performance DSP and AFE semiconductors. GlobeSpan's high level of systems expertise results in DSL chipset solutions that lead the industry in meeting equipment suppliers' time-to-market, power, package density, and performance needs.

The independent testing performed by GlobeSpan and ADTRAN is in addition to the industry-sponsored HDSL2 Consortium interoperability testing efforts, in which both companies are participants. Interoperability testing will expedite the delivery of interoperable products to market.

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 GlobeSpan

GlobeSpan, Inc. is a leading worldwide developer of advanced digital subscriber line (DSL) integrated circuits, which enable high-speed data transmission over the existing network of copper wire telephone lines at rates over 100 times faster than today's commonly deployed 56 kilobit modem technologies. GlobeSpan has leveraged seven years of field experience in implementing DSL technology to successfully bring proven DSL chipset solutions to market. The company's core engineering team includes several individuals who were early developers of DSL technology at AT&T Bell Labs. GlobeSpan offers a broad suite of DSL solutions, including ADSL, HDSL, HDSL2 and SDSL chipsets based on 2B1Q, CAP, DMT and PAM line codes.

GlobeSpan, Inc. is based at 100 Schulz Drive, Red Bank, New Jersey 07701 and can be reached at 732/345-7500. The company's web site is http://www.globespan.net.

This press release contains forward-looking information within the meaning of Section 21E of the Securities Exchange Act of 1934, and is subject to the safe harbors created by this section. These forward-looking statements concern, among other things, the future market for DSL chipsets. The matters discussed in this news release involve risks and uncertainties described from time to time in GlobeSpan's filings with the Securities and Exchange Commission, particularly in the Risk Factors section relating to the rapid changes in the DSL market, competition and limited protection of GlobeSpan's intellectual property set forth in the final prospectus for GlobeSpan's initial public offering, dated June 23, 1999, as well as GlobeSpan's most recent Quarterly Report on Form 10-Q. GlobeSpan assumes no obligation to update the forward-looking information contained in this press release.