Milpitas, Calif. October 9, 2001 - Aperto Networks, a leading developer of second-generation fixed broadband wireless access systems, today announced that it has joined the partner program of Sonus Networks (NASDAQ: SONS), a leading provider of voice infrastructure solutions for the new public network. This partnership expands Aperto's multiservice delivery capability by enabling Voice over IP (VoIP) features for wireless carriers who do not deploy Class 5 switches.

Sonus Networks' Open Services Partner Alliance (OSPA) brings together best-of-breed technologies to offer end-to-end and converged network solutions through interoperability for service providers worldwide. "We are happy to have Aperto Networks join the OSPA," said Terri Griffin, Sonus' vice president of marketing. "Wireless carriers have shown strong interest in bringing the benefits of packet technology to their networks. We look forward to exploring future opportunities in this emerging market."

"By becoming an OSPA member, we join an alliance that is dedicated to providing a new generation of standards-based packet voice solutions," stated Aperto Networks' vice president of marketing Alan Menezes. "This will allow us to accelerate one of Aperto's key technology and market goals: to help fixed wireless access become a ubiquitous alternative for broadband service deployment."

To ensure high quality packet voice, Aperto's PacketWave™ system uses an advanced QoS technology, ServiceQ™, to prioritize voice and other real-time traffic delivery by user and by application. In addition, its OptimaLink™ dynamically optimizes up to ten PHY and MAC-layer parameters to each wireless subscriber. This expands coverage of previously inaccessible areas due to obstructed-line-of-sight or non-line-of-sight conditions, and provides subscribers with high reliability and robust network performance. These technologies are key to making wireless broadband a preferred access alternative.

The PacketWave system consists of the PacketWave 1000 Base Station, PacketWave 100 Series Subscriber Units, WaveCenter™ Subscriber Management Tools, radios and antennas for 2.5, 3.5, 5.3, and 5.8 GHz bands. PacketWave for 5GHz frequencies has been shipping since late August 2001, and systems have been deployed in production and trial networks at multiple carriers in North America, Europe and Asia.

About Aperto Networks
Aperto Networks is a developer of multi-service fixed broadband wireless access systems. The company was founded to provide a breakthrough solution to one of today's critical network bottlenecks - last-mile broadband access. With practical, scalable systems and patent-pending technology that support new wireless builds and complement existing wireline broadband access technology, Aperto addresses service provider needs for rapid network deployment, multiservice scalability, ease of installation and cost-effectiveness. Aperto will dramatically shorten the lengthy provisioning cycles of broadband services by enabling rapid service provisioning across dense urban to suburban locations. Investors in Aperto include Alliance Ventures, Tyco Ventures, Ridgewood Capital, Satwik Ventures, DMC Stratex Networks, Oki Electric Industry Company, Mitsubishi International Corporation, Redwood Ventures and Solar Venture Partners. For more information on Aperto Networks, go to www.apertonet.com.

About Sonus' OSPA
Founded on the combination of Sonus' Open Services Partner Alliance (OSPA) Program and the INIP PoweredSM Partner Program from the acquisition of telecom technologies, inc., the OSPA has gained significant industry momentum, with membership of more than 150 leading independent vendors. The OSPA provides a framework that offers service providers end-to-end packet-based network solutions using best-of-breed technologies and applications. The goal of the OSPA is to empower standards-based interoperability between applications, hardware vendors, and the Sonus product suite. An integral part of the Sonus OSPA, the Interoperability Laboratory in Richardson, Texas, is the first in the industry where product interoperability is verified, trial testing is performed, and complete solutions are ultimately produced. Additional information on the OSPA is available at http://ospa.sonusnet.com.

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