21st Century Communications World Forum - Stand 1000

SWINDON, UK, 14 February 2005 - Sonus Networks (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, today announced that it is participating in the inaugural 21st Century Communications World Forum being held February 21-24 at the Royal Lancaster Hotel, London, UK.

The 21st Century Communications World Forum comprises an education-centric conference and exhibition focused on transitioning from a legacy infrastructure and the impact of convergence on the industry. The exhibition features technology demonstrations by leading IP equipment suppliers and innovators, while the educational-forum will bring together industry visionaries and senior executives from service providers and technology vendors from around the globe.

Participating at the event, Sonus Networks will feature its industry leading VoIP technology, applications and enhanced services, which are deployed worldwide to facilitate the transformation of fixed and mobile networks to VoIP. Sonus will also be chairing a panel session at the conference, focusing on the deployment of enhanced SIP services on a carrier network. Sonus, along with executives from BT, T-Systems and Interoute, will discuss their experience in the implementation of a next generation multi-services platform built for the requirements of the 21st century. The panel will also explore future opportunities brought about by the global reach of 21st century IP-based networks.

Neil Kinder, Technical Director EMEA, Sonus Networks, will chair the following session:

Service Provider Deployment Case Studies and Business Models: Deployment of Enhanced SIP Services on a Carrier Network

Date:Thursday, 24th February 2005
Time: 13.30 - 15.00 (Session G2)
Guest Speakers: Alan Nunn, Chief Voice Architect, OCTO, BT Dietmar Geiler, VP Product Marketing, Global Voice, VPN Services, T-Systems Matthew Finnie, VP Service Development and Systems, Interoute

The 21st Century Communications World Forum conference and exhibition is presented by the International Engineering Consortium (IEC), and host sponsored by BT. Further information on the 21st Century Communications World Forum can be found at http://www.iec.org/events/2005/21/ .

About Sonus Networks

Sonus Networks, Inc. is a leading provider of packet voice 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, residential access and Centrex, tandem switching, and IP voice termination, as well as enhanced services. Sonus' award-winning 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. For more information, visit 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 November 9, 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. 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 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.