PairGain Announces HDSL2 Support on Avidia System; HDSL2 Technology on Display at PairGain's Booth No. 1418.

WASHINGTON, D.C.--(BUSINESS WIRE)--Jan. 26, 1999--PairGain(R) Technologies, Inc. (Nasdaq:PAIR) Tuesday announced support of HDSL2 in its Avidia(TM) System integrated access concentrator.

HDSL2 delivers the same reliable performance of two-pair HDSL over a single copper telephone line. The T1E1.4 committee-approved transmission scheme enables HDSL2 to coexist in the same cable bundle with T1, HDSL, ADSL and ISDN. HDSL2 uses the OPTIS line code originally proposed by PairGain and standardized by T1E1.4.

The new Avidia System interface provides eight HDSL2 or T1 connections, each transmitting at a 1.544 Mpbs symmetric rate. The Avidia System has 18 slots for plug-in channel cards providing ATM concentration, traffic management and QoS (Quality of Service) for up to 144 HDSL2 T1 ports carrying voice, data and video. The eight HDSL2 interfaces on each channel card support Inverse Mux ATM (IMA) for T1, which allows multiple ports to be utilized as a single, higher capacity ATM connection to meet the dynamic capacity needs of business customers.

"It is PairGain's mission for the Avidia System to be the single platform required by carriers to terminate local loop services. New services are being defined every day, and the cost to carriers of adding a new type of access platform for each new service is extreme," said Howard Flagg, executive vice president of business development at PairGain.

"The Avidia System's architecture provides ATM switching plus room for service adaptation. This enables it to support a range of ATM and IP services over any type of DSL transport, ultimately providing a gateway for all legacy traffic into the ATM backbone."

Flagg continued, "As carriers establish POPs over broad areas, they will find great benefit in minimizing the number of platforms that must be installed. The economics of access systems will be based on the variety of services supported per system, not just on dollars per DSL channel."

The Avidia System's HDSL2/IMA-T1 interface also enables connection of integrated access devices (IADs) at the customer premises on multiple T1 lines. This conforms to the ATM Forum's Specification 1.1 (AF-PHY-0086.001), a standard that is expected to gain wide industry support. PairGain anticipates that the new generation of ATM IADs will comply with the standard, allowing easy provisioning through the Avidia System, using standard HDSL2 to DS1 converters at the network interface or direct connecting when IADs incorporate the HDSL2 feature.

The HDSL2/IMA-T1 interface enables economic connection of remote Avidia Systems to the ATM network. Traffic management and traffic policing features ensure that higher classes of service are prioritized per the requirements of their underlying applications. Without traffic management and IMA, ATM access multiplexers and DSLAMs must use high-cost OC-3 and DS-3 connections to the ATM backbone to guarantee that peak loads will not result in the loss of user traffic.

PairGain's HDSL2 technology is on display here at ComNet in booth no. 1418. The HDSL2/IMA feature will be available on the Avidia System in early Q3, 1999.

PairGain Technologies Inc.

PairGain is a world leader in the design, manufacture and marketing of DSL (Digital Subscriber Line) networking systems. Service providers and private network operators worldwide use PairGain's products to deploy DSL-based services such as high-speed Internet, remote LAN access and enterprise LAN extension.

For more than 10 years, PairGain has been recognized as the technological leader and industry innovator of telecommunications equipment. The company offers the widest range of HDSL, ADSL and SDSL-based systems available. Its product lines include HiGain(R) T1/E1 access systems, PG-Flex(R) and PG-Plus(R) small digital loop carrier systems, the Avidia(TM) System and Megabit Modem(R) campus systems and megabit access products. Well over 1 million PairGain DSL nodes are installed in over 70 countries. Additional information about the company is available on the Internet at www.pairgain.com

Except for the historical information contained herein, the matters discussed in this announcement are forward-looking statements which involve risks and uncertainties, including but not limited to economic, competitive, governmental and technological factors affecting the company's operations, markets, products, services and prices and other factors discussed in the company's filings with the Securities and Exchange Commission.