For more information, please contact:

CHELMSFORD, Mass., July 21, 2004 – Sonus Networks (Nasdaq: SONSE), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, today announced the appointment of Steve Edwards as chief marketing officer (CMO) and general manager of Europe, Middle East and Africa (EMEA). In this role, Edwards reports to Sonus president and chief operating officer (COO), Bert Notini.

As a senior executive with over 25 years experience in the global telecommunications and IT industry, most recently as vice president of indirect sales and strategic partnerships at AT&T, Edwards will lead Sonus Networks’ global marketing, product management and business alliances activities. In addition, Edwards will assume responsibility for business operations within EMEA.

Under Edwards, the consolidation of all marketing, product management and business alliances initiatives will provide a focus on delivering high-value VoIP solutions and services to wireless and wireline service providers and immediately creating strategic alliances and partnerships to increase global coverage.

“Steve has achieved success in both large, multinational telecommunications organizations and in start-up environments, and will be key in driving Sonus’ growth,” said Hassan Ahmed, chief executive officer (CEO) and chairman, Sonus Networks. “Steve brings to Sonus considerable knowledge and leadership in building global partnerships and the development of high-growth sales channels and strategies. We are delighted to welcome Steve to the Sonus management team.”

“Sonus is widely regarded as a pioneer in VoIP technology, is well positioned in a fast-growing market and possesses a culture geared for success,” commented Edwards. “I am excited to take on this opportunity, and look forward to extending Sonus’ leadership in this market.”

At AT&T, Edwards was responsible for AT&T’s channel partner program, strategic alliances and the overall distribution model for AT&T Business. Prior to that, Edwards held executive positions with Concert (a global joint venture company), including COO for global services, and vice president of service delivery, where he was responsible for delivering voice and data services in over 50 countries via regional service providers. As president of BT Visual Images, Edwards led the videoconferencing start-up through a successful IPO and acquisitions.

Edwards held various positions in engineering, product development and product marketing at British Telecommunications (BT) and holds a bachelors degree in electrical and computer systems engineering from Loughborough University of Technology (UK).

About Sonus Networks

Sonus Networks, Inc. is a leading provider of voice over IP (VoIP) infrastructure solutions for wireline and wireless service providers. With its Open Services Architecture (OSA), Sonus delivers end-to-end solutions addressing a full range of carrier applications, including trunking and tandem switching, residential and business access, network border switching and enhanced services. Sonus' voice infrastructure solutions, including media gateways, softswitches and network management systems, are deployed in service provider networks worldwide.

Sonus, founded in 1997, is headquartered in Chelmsford, Massachusetts. Additional information on Sonus is available at http://www.sonusnet.com.

Sonus is a registered trademark of Sonus Networks. Open Services Architecture, GSX9000, Insignus and Sonus Insight are trademarks of Sonus Networks. All other trademarks, service marks, registered trademarks, or registered service marks are the property of their respective owners.