Global Crossing Reaches New Milestones With Sonus Networks-based VoIP Infrastructure

• Global Crossing more than doubles VoIP traffic and achieves reliability metrics with Sonus Networks.
• Company leads market in minutes of use, scope of network.
  

Florham Park, N.J. and Chelmsford, Mass. - May 17, 2004 - Global Crossing (NASDAQ: GLBCE) and Sonus Networks, Inc. (NASDAQ: SONSE), today announced that Global Crossing has achieved important new milestones with its voice over IP (VoIP) network, which is supported by Sonus Networks' industry-leading packet voice infrastructure solutions.

Global Crossing exceeded its network traffic goals for 2003, and in March 2004 carried more than 2.4 billion minutes of traffic on its VoIP network. Sonus' VoIP platform continued to surpass Global Crossing's platform availability objectives, delivering five nines availability for all of 2003 and 2004 year-to-date.

"This milestone is yet another proof point in our success with voice services over our global IP-based network," said John Legere, Global Crossing's chief executive officer. "As we continue enhancing our VoIP offering for both carriers and enterprises, we look forward to our continued success and relationship with Sonus Networks."

Global Crossing more than doubled the traffic transmitted on its VoIP network between January 2003 and March 2004, growing from 1.16 billion minutes per month to 2.4 billion minutes per month. At the same time, Global Crossing boosted the availability of its network, recording 99.999 percent uptime for 2003 and year-to-date 2004.

"Four years ago, Global Crossing was one of the first service providers to make the transition to a VoIP network, and they continue to lead the way," said Hassan Ahmed, CEO and chairman, Sonus Networks. "Today, Global Crossing owns one of the largest operating VoIP networks in the world -- one that truly delivers carrier-grade quality and availability. We are extremely proud to have worked with Global Crossing to develop this network, and we look forward to continuing as their partner in this endeavor."

Global Crossing began offering service on its carrier-class VoIP network in September 2000, and today owns one of the industry's largest operating VoIP network in terms of both minutes of use and number of points of presence (PoPs). Global Crossing's network encompasses 27 VoIP gateway centers in 10 countries throughout North America, Europe, and Latin America, providing connectivity to enterprise and carrier customers worldwide.

Global Crossing has built its network on Sonus' Open Services Architecture™ (OSA) and VoIP infrastructure solutions, including the GSX9000O Open Services Switch, the Insignus™ Softswitch and the Sonus Insight™ Management System. Global Crossing expects to transmit more than 40 percent of its voice traffic over its VoIP network by the end of 2004.

ABOUT GLOBAL CROSSING
Global Crossing (Nasdaq: GLBCE) provides telecommunications solutions over the world's first integrated global IP-based network. Its core network connects more than 300 cities and 30 countries worldwide, and delivers services to more than 500 major cities, 50 countries and 6 continents around the globe. The company's global sales and support model matches the network footprint and, like the network, delivers a consistent customer experience worldwide.

Global Crossing IP services are global in scale, linking the world's enterprises, governments and carriers with customers, employees and partners worldwide in a secure environment that is ideally suited for IP-based business applications, allowing e-commerce to thrive. The company offers a full range of managed data and voice products including Global Crossing IP VPN Service, Global Crossing Managed Services and Global Crossing VoIP services, to more than 40 percent of the Fortune 500, as well as 700 carriers, mobile operators and ISPs.

Please visit www.globalcrossing.com for more information about Global Crossing.

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 www.sonusnet.com.

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

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Statements made in this press release that state Global Crossing's intentions, beliefs, expectations, or predictions for the future are forward-looking statements. These statements contain words such as "anticipate," "estimate," "expect," "project," "intend," "plan," "believe," "will," or similar expressions. Such statements are subject to known and unknown risks, uncertainties and other factors that could cause the actual results to differ materially from those contemplated by the statements, including the results of the ongoing review of Global Crossing's cost of access liabilities and cost of access operating expenses and the related control environment, and the impact of the expected restatement, as well as the reaction of the company's shareholders, customers, vendors and prospective lenders; the company's history of substantial operating losses and the fact that, in the near term, funds from operations will not satisfy cash requirements; the ability of the company to arrange the necessary financing to fund its liquidity requirements; the likelihood that the prices the company charges for its services will continue to decrease; the company's ability to continue to connect its network to incumbent carriers' networks or maintain Internet peering arrangements on favorable terms; the consequences of any inadvertent violation of the company's Network Security Agreement with the U.S. Government; the impact of actual and potential customers' bankruptcies on the company's sales prospects and results of operations; increased competition and pricing pressures resulting from technology advances and regulatory changes; competitive disadvantages relative to competitors with superior resources; the impact on the company's competitiveness of its technology choices; the company's dependence on third parties for many functions; political, legal and other risks due to the company's substantial international operations; and other risks referenced from time to time in Global Crossing's filings with the Securities and Exchange Commission. Global Crossing undertakes no duty to update information contained in this press release or in other public disclosures at any time.

This release may contain projections or other forward-looking statements regarding future events or the future financial performance of Sonus Networks 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 "Cautionary Statements" section of Sonus' Quarterly Report on Form 10-Q, dated November 10, 2003 and filed with the SEC, which identifies important risk factors that could cause actual results to differ from those contained in the forward-looking statements. Risk factors include, among others, uncertainties regarding the timing of the Company's completion of the audit and filing of its Annual Report on Form 10-K/A for 2003 and future periodic reports, risks as to the SEC's investigation of these or other matters, unforeseen issues encountered in the completion of the audit, uncertainties regarding the extent to which prior period financial statements will be restated, the continued adverse effect of developments in the telecommunications industry, Sonus' ability to grow its customer base, dependence on new product offerings, market acceptance of its products, competition from large incumbent vendors, rapid technological and market change and manufacturing and sourcing risks. 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.