ADTRAN Introduces New ISDN Remote Access Devices for High Speed Connectivity.

CHICAGO--(BUSINESS WIRE)--June 5, 1996--ADTRAN, Inc., (NASDAQ:ADTN) introduced today, at the Comdex trade show in Chicago, two new ISDN remote access devices that allow high-speed connectivity for telecommuting, internet access, and small office/home office applications. The Express XL and Express XLT are standalone devices featuring concurrent IP routing and bridging as well as terminal adapter and NT1 functionality. The Express XL is a data only device with an ethernet connection while the Express XLT provides an ethernet connection and one analog port for an analog device such as a telephone, fax machine, or analog modem. The Express XL/XLT provides greater network flexibility allowing multiple computers to share a single ISDN line.

"The Express XL/XLT provides an ethernet interface which is well suited for high speed connectivity," said Leslie Conway, ADTRAN ISDN Product Manager. "These products were designed for the user who wants to overcome the performance limitations of RS-232 serial connections."

The Express XL/XLT supports data rates to 128 kbps without compression. For even higher rates, the units support STAC LZS compression as a standard feature. This compression also interoperates with the Ascend compression used by many internet service providers.

The Express XL/XLT also makes connecting to ISDN easy. ISDN setup can be difficult due to ISDN line parameters provided by the telephone company. Sophisticated patent pending algorithms automatically detect the telephone company parameters such as Switch type and SPID numbers, easing the complexity commonly associated with the installation of ISDN equipment.

Today IP addresses are at a premium. The Express XL/XLT conserves IP addresses when a single computer is connected to the unit. In Single User IP mode, the XL/XLT allows dynamic address assignment from an ISP or central site router. This provides the Express XL/XLT and computer to use one IP address instead of requiring two.

Additional features include extensive filtering capabilities, dynamic bandwidth management and comprehensive security. Filtering capabilities allow for controlling bridged traffic, conserving bandwidth, and securing the local LAN. Quick Setup configuration profiles contain predefined MAC, pattern, and IP filters for popular applications. Dial-on-demand capabilities allow connections to automatically be established and disconnected based on thresholds and user demand. The Express XL/XLT addresses the need for network security by supporting server and client password protection, PAP, CHAP, Caller ID, and Security Dynamics' SecurID. In addition, the Express XL/XLT supports TELNET and SNMP management using MIB II over the LAN and WAN interfaces.

The list price for the Express XL is $995 and the Express XLT is $1,095 with production availability in July 1996.

ADTRAN was established in 1985 to design, develop and manufacture advanced transmission products for high-speed digital communications. In addition to its HDSL products, ADTRAN is a primary provider of DDS and ISDN digital loop products to Regional Bell Operating Companies and many well known OEMs. The broad selection of customer premises products offered by ADTRAN includes a complete line of DSU/CSUs, a variety of ISDN extension and network terminating products and flexible T1 multiplexers. For more information regarding ADTRAN and its products, call 1-800-326-3700, fax [phone], or E-Mail: [e-mail]. ADTRAN can be found on the Internet at www.adtran.com.

CONTACT: ADTRAN Inc.

Stacy Thomas, 205/971-8488

[e-mail]

Leslie Conway, 205/971-8729

[e-mail]