ADTRAN Introduces a Compact, High-Density, Multiservice SONET Fiber Multiplexer; OPTI-MX Delivers Hi-Cap Transport, Ethernet Over SONET.

Business Editors/High-Tech Writers

HUNTSVILLE, Ala.--(BUSINESS WIRE)--May 13, 2003

ADTRAN(TM), Inc. (NASDAQ: ADTN), The Network Access Company and leading provider of telecommunications equipment, today announces a new integrated, high-density SONET fiber multiplexer. The Total Access(R) OPTI-MX(TM), delivers 10/100 Ethernet, DS3s, DS1s (VT1.5), OC-3s and STS-1s. In just 2U of rack space, this OC-3/OC-12 multiplexer delivers a full suite of services, including Ethernet over SONET and sets a new standard for price, performance and size.

"The Total Access OPTI-MX expands our fiber access product line by adding integrated service delivery," states Jay Wilson, director of product management for ADTRAN's Carrier Networks Division. "It enhances our focus on reducing the cost of fiber access, just as we have reduced the cost of service delivery over copper."

The Total Access OPTI-MX features extensive maintenance and operational capabilities and employs TL-1, SNMP, and ADTRAN's interactive menuing system. The OPTI-MX integrates seamlessly into today's networks and provides DCC interoperability with GR-253 compliant SONET network elements.

The design of the OPTI-MX simplifies deployment, increases reliability and provides immediate cost savings through ADTRAN's value engineering and high-density application circuit design. Access to up to 84 redundant DS1s is supported in a single temperature-hardened system with simultaneous support for DS3, STS-1 and Ethernet tributaries, with no stranded bandwidth. The integrated service capabilities of the OPTI-MX allows carriers to seamlessly deliver IP/Ethernet while also reducing the cost of their existing TDM offerings. The OPTI-MX is Telcordia(TM) OSMINE, NEBS Level 3 compliant and features optional optical and electrical protection.

ADTRAN strives to understand the needs of telcos and service providers, and designs products such as the Total Access OPTI-MX to meet cost, operational, and growth objectives for its customers.

About ADTRAN

ADTRAN, Inc. is an established provider of advanced transmission products for today's expansive telecommunications networks. ADTRAN products support most major technologies, including internetworking, access routing, fiber, T3, T1, E1, E3, wireless T1/E1, ATM, Frame Relay, IP, VPN, ADSL, SHDSL, SDSL, HDSL, HDSL2, HDSL4, SONET, SDH, ISDN, and DDS. According to Gartner/Dataquest and IDC, ADTRAN has gained the leading market position in enterprise integrated access devices and HDSL, while maintaining its leadership position for the fourth year in a row in T1 and sub rate CSU/DSUs, Frame Relay/DDS extension, and ISDN extension. ADTRAN equipment serves the major Incumbent Local Exchange Carriers, Independent Telephone Companies, interexchange carriers, ISPs, Competitive Local Exchange Carriers, international service providers, public and private enterprises, and original equipment manufacturers.

ADTRAN products are RUS accepted and feature a five or ten-year warranty on every product. For more information, contact the company at 800 9ADTRAN (800 923-8726) or via e-mail at [e-mail]. On the web, visit www.adtran.com.