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Revenues Increase 16% Sequentially, Profits Increase to $0.02 Per Share;
Company Becomes Current On All Financial Reporting Requirements

CHELMSFORD, Mass., August 20, 2004 – Sonus Networks (SONS.PK), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, today reported its financial results for the second quarter ended June 30, 2004. Sonus today also filed its Form 10-Q for the second quarter of 2004 with the Securities and Exchange Commission (SEC). Sonus will hold a conference call to review its financial results at 8:00 am Eastern time, Monday, August 23, 2004.

Revenues for the second quarter of fiscal 2004 were $42.4 million compared with $36.5 million for the first quarter of fiscal 2004 and $15.4 million for the second quarter of fiscal 2003. Net income for the second quarter of fiscal 2004 was $4.9 million or $0.02 per share compared with a net income of $3.0 million or $0.01 per share for the first quarter of fiscal 2004 and a net loss of $7.3 million or $0.03 per share for the second quarter of fiscal 2003.

Revenues for the first six months of fiscal 2004 were $78.9 million compared with $24.6 million in the same period last year. Net income for the first six months of fiscal 2004 was $7.9 million or $0.03 per share compared with a net loss for the first six months of fiscal 2003 of $17.0 million or $0.08 per share.

Today’s filing of Sonus’ Quarterly Report on Form 10-Q for the second quarter brings the Company into full compliance with the SEC periodic financial statement reporting requirements. The Company has notified Nasdaq of its filing and will immediately apply for re-listing on The Nasdaq National Market.

With today’s filings, we have successfully regained compliance with SEC reporting requirements,” said Hassan Ahmed, chief executive officer and chairman, Sonus Networks. “While it would have been easy to become distracted or lose momentum during this time, we remained focused on winning new business, expanding our market presence and delivering new solutions and services, and the results we are reporting to you today underscore this. We are pleased with our performance for the second quarter and are optimistic about the opportunity ahead of us.”

Sonus’ growth in the second quarter was fueled by an increasingly diversified customer base, as new customers selected Sonus for their VoIP networks and existing customers expanded their deployments. Reflecting this growth and diversity, AT&T Wireless, Qwest Communications and Volo were each 10% customers for the second quarter. In May, Global Crossing announced that it had achieved several important milestones with its Sonus-based network. Global Crossing more than doubled the minutes of traffic running on its VoIP network between January 2003 and March 2004, and also boosted the reliability of its network, recording 99.999 percent availability for the same period. Also in the quarter, Volo Communications implemented Sonus’ VoIP infrastructure solutions to enhance its nationwide IP backbone network.

As testament to its success with its customers, independent industry research firms again recognized Sonus as the number one provider of carrier voice over IP (VoIP) infrastructure. Synergy Research Group and In-Stat/MDR issued first quarter market share reports naming Sonus as the market share leader in several segments of the VoIP equipment market.

At SUPERCOMM 2004, Sonus further extended its technology advantage, launching access solutions to facilitate carriers’ deployment of voice over broadband (VoBB) services for consumers and enterprises. Sonus’ VoBB solution delivers basic local area calling features as well as advanced IP-based functionality over broadband technologies including DSL and cable, providing a lower-cost and flexible alternative for residential and enterprise telephone services. Additionally, Sonus also announced that its InsignusTM Softswitch featuring the ASX Access Server provides enhanced services via WiFi devices.

Company Conference Call, Webcast and Replay Information

Date: Monday, August 23, 2004
Time: 8:00 am Eastern

To listen via telephone:

Dial-in number: +1-800-726-6572 or +1-415-908-6280

To listen via the Internet:

Sonus will host a live webcast of the conference call. To access the webcast, visit the Sonus Networks Investor Relations site at http://www.sonusnet.com.

Replay:

A telephone playback of the call will be available following the conference and can be accessed by calling +1-800-633-8284 or +1-402-977-9140. The access code for the replay is 21205824. The telephone playback will be available through Tuesday, September 7, 2004.

The webcast will be available on the Sonus Networks Investor Relations site through August 23, 2005. To access the replay of the webcast, visit the Investor Relations site at http://www.sonusnet.com.

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 ArchitectureTM (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.

This release may contain forward-looking statements regarding future events 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 the “Risk Factors” section of Sonus’ Annual Report on Form 10-K/A dated July 28, 2004 and filed with the SEC, and the “Cautionary Statements” section of Sonus’ Quarterly Report on Form 10-Q, dated August 20, 2004 and filed with the SEC, which identify important risk factors that could cause actual results to differ from those contained in the forward-looking statements. Risk factors include, among others, the possibility that Sonus may not be re-listed on the The Nasdaq National Market and risks associated with the pending securities litigation and SEC investigation. In addition, any forward-looking statements represent Sonus’ views only as of today and should not be relied upon as representing Sonus’ views as of any subsequent date. While Sonus may elect to update forward-looking statements at some point, Sonus specifically disclaims any obligation to do so.

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.