Sonus Networks Continues to Build Momentum With Open Services Partner Alliance; Five Telecom Companies Join OSPA; Membership in Alliance Stands at More Than 40 Vendors.

Business/Technology Editors

WESTFORD, Mass.--(BUSINESS WIRE)--Sept. 12, 2000

Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, announced that it has expanded its Open Services Partner Alliance(TM) with the addition of five new members. Companies joining the Alliance today include: Avant Telecoms, Innovative Systems, Integral Access, NexTone Communications and VocalData. The OSPA, which has a membership of 42 leading telecom companies, facilitates the rapid development and delivery of competitive new services by carriers, application service providers and third-party independent service developers.

"We're very pleased to welcome these new partners into the Alliance, which now offers service providers even greater options for delivering voice and data services in the new public network," commented Gary Rogers, Sonus' vice president of worldwide sales and marketing. "We look forward to working closely together to help our carrier customers differentiate themselves through a range of enhanced service offerings."

Sonus' newest partners in the OSPA offer telecommunications carriers a variety of software and hardware solutions and services:

-- Avant Telecoms provides turnkey solutions for telecommunications projects requiring expertise in systems engineering, high-level solution design, documentation services and project management.

-- Innovative Systems has developed a multi-function, SCP-like service platform that combines the telephony and Internet infrastructures with Advanced Intelligent Network (AIN) and service creation environment (SCE).

-- Integral Access delivers PurePacket, a multi-service access system that uses MPLS to route, transport and switch voice and data transmissions in packet format, and supports the GR-303 and MGCP standards for enabling competitive carriers to offer differentiated services across IP-based networks and traditional circuit-switched infrastructures.

-- NexTone Communications provides the iVANi system, a range of customer premise equipment and application servers designed to ease the deployment of enhanced voice, data and fax services, lower access costs and improve operational efficiencies.

-- VocalData offers the VOISS(TM) solution, an open, standards-based service delivery softswitch that allows service providers to offer voice services and enhanced voice applications to businesses over next generation networks.

About Sonus' OSPA

Launched in June 1999, the OSPA has gained significant industry momentum, with membership of 42 leading independent vendors offering subscriber-specified and user-provisioned services for the new public network. The OSPA gives carriers the flexibility to both develop and integrate "best-of-breed" applications, creating important new revenue streams. For participating partners, the OSPA provides open, published APIs, comprehensive developer tools, testing and support services, technology exchanges and co-marketing and sales activities. Equally important, the Alliance provides a unified customer/vendor forum for creating interoperable standards and technologies. Additional information on the OSPA is available at www.sonusnet.com/partners.

About Avant Telecoms

Avant Telecoms Inc. is a telecommunications project specialist company, primarily working on systems integration, software and product development for fixed-line network carriers, cellular operators and government agencies, and has the local expertise and staff to carry out the project requirements. Avant specializes in solutions for the radio, fiber optic and digital multiplex industry and supports a large range of products for this market.

About Innovative Systems

With an installed base of over 200 systems, Innovative Systems is a major supplier of advanced services. The company offers custom service creation using AIN and ISUP, as well as many currently available Advanced Services. Clients can download Advanced Services directly from the company's e-commerce Web site. Clients include ILECs, CLECs, traditional and next generation switch manufacturers, and STP providers. For more information on Innovative Systems, visit www.innovsys.com.

About Integral Access

Integral Access, Inc. provides multi-service MPLS-based access systems for communications services providers. The company offers a complete access network solution, which includes customer premise equipment, central office aggregation devices, and an operations management system for network control and services management. To contact Integral Access call [phone], visit the company on the Web at http://www.integralaccess.com, or write to [e-mail].

About NexTone Communications

Founded in 1998 and headquartered in Rockville, Maryland, NexTone Communications is a provider of advanced networking systems that power the Virtual Central Office. The Virtual Central Office enables next-generation service providers to deliver convergent voice and IP services in the most simple and cost effective way. NexTone Communications is a Safeguard Scientifics (NYSE: SFE) partner company. You can learn more about NexTone at www.nextone.com.

About VocalData

VocalData Inc., based in Richardson, Texas, develops and markets service delivery softswitches and enhanced services platforms that enable communications carriers to deliver advanced telephony and communications services on next generation networks (NGNs). VocalData's Voice over IP Softswitch (VOISS (TM) ) platform is the only complete NGN solution available today for offering local telephony services: service delivery softswitch, gateway, enhanced services platforms, and IP end-points. The Company's product suite was awarded the prestigious SUPERQuest "Most Promising New Public Networks Technology" award at the SUPERCOMM show in June 2000. For more information, visit their Web site at www.vocaldata.com.

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice infrastructure products for the new public network. Sonus' solutions enable service providers to deploy an integrated network capable of carrying both voice and data traffic, and to deliver a range of innovative, new services. The Sonus Open Services Architecture(TM) (OSA) and award-winning Packet Telephony suite cut the time-to-market for competitive new service products, allowing carriers and third-party developers to expand marketshare and build important new revenue streams. Its highly scalable products fully interoperate with and extend the life and utility of today's public network. Sonus embodies in its management and staff decades of experience in developing carrier-class voice, data and multimedia solutions for implementation in the world's largest networks. Sonus, founded in 1997, is headquartered in Westford, Massachusetts. Additional information on Sonus is available at http://www.sonusnet.com.

This release may contain projections or other forward-looking statements regarding future events or the future financial performance of Sonus that involve risks and uncertainties. Readers are cautioned that these forward-looking statements are only predictions and may differ materially from actual future events or results. Readers are referred to Sonus' Quarterly Report on Form 10-Q for the quarter ended June 30, 2000, filed with the SEC, which identifies important risk factors that could cause actual results to differ from those contained in the forward-looking statements. These risk factors include, among others, the Company's ability to grow its customer base, dependence on new product offerings, market acceptance of our products, rapid technological and market change and manufacturing and sourcing risks.

Open Services Partner Alliance and Open Services Architecture are trademarks of Sonus Networks. All other company and product names may be trademarks of the respective companies with which they are associated.