Sonus Networks Expands Open Services Partner Alliance with Addition of Eleven Telecom Vendors

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Alliance Offers Service Providers End-to-End Packet Network Solutions; Membership Grows to More Than 100 Partners

WESTFORD, Mass., March 19, 2001 - Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today announced it is continuing to build and broaden its Open Services Partner Alliance(TM) (OSPA) through partnerships with 11 leading telecom vendors. Sonus' OSPA includes more than 100 members that help bring a broad spectrum of revenue-generating services to the carrier market with solutions ranging from enhanced services to network infrastructure products and operations support systems. The newest members of the Alliance include Acterna, ECI-NGTS, HearMe, MIND, NetEffect, Switch Management, Tango Telecom, Telecom Software Enterprises, Tundo, VINA Technologies and Zenfinity.

"We are extremely pleased with the continuing acceptance and growth of our partner program," said Terri Griffin, vice president of marketing, INtelligentIP(R) division, Sonus Networks. "Each member company brings a unique solution to the Alliance and assists our customers in offering exciting new services to end users. Together with our partners, we are helping carriers deliver on the promise of the new public network by making it easier to deploy an extensive range of voice and data solutions."

Companies joining the Sonus OSPA today offer a wide range of enhanced services, infrastructure products and OSS solutions to carriers and service providers:

• Acterna's NetOptimize Capacity Manager is a performance management solution that supports data collection from both tandard and emerging technologies including digital central office switches, ATM switches, frame relay switches, wireless switches, private branch exchanges, SS7 networks, and computer networks. The OSS solution is equipment independent and can be scaled to accommodate small or large networks, thus growing with the increasing needs of the service provider.
• ECI-NGTS manufactures high quality, carrier-class packet telephony solutions. The company offers new voice infrastructure media gateways based on H.323, MGCP, H.248 and SIP protocols; SIP-based IP telephony networking solutions; and business applications that bridge the IP and classic telephony domains.
• The HearMe(TM) VoiceSERVER(TM) VoIP application platform simplifies and speeds deployment of enhanced services for next generation networks. The technology offers application development using Web-based tools or APIs, H.323 and SIP call support, presence detection, multipoint conferencing, and PC, phone, or wireless handset access. A suite of ready-to-run applications provides VoIP conferencing, VoIP calling, and VoIP commerce/call center functionality to help jump-start a provider's deployment efforts.
• MIND CTI is a leading provider of billing and customer care, accounting, and management solutions for multiple IP services including voice, data, content and unified messaging. MIND's convergent IP services billing system provides ISPs, ITSPs and telcos with a real time solution for billing diverse IP services.
• NetEffect bridges the gap between the introduction of next-generation communications applications and the infrastructure of client networks by designing, implementing and managing emerging networked applications and technologies. NetEffect's solutions include Voice over IP, interactive call center technologies and communications infrastructure.
• Switch Management is an OSS software vendor that provides carrier billing and QoS monitoring products to wholesale and international telecom carriers. Its flagship product is WebCDR, a web-based wholesale billing ASP that features automated data collection, processing, reporting, and bill presentment -- all via the Internet.
• Tango Telecom provides enhanced services such as number portability, VPN, and 2G and 3G mobile prepaid for the competitive telecommunications market in both circuit and packet networks. With the evolutionary Tango INgate(TM) product, operators using Sonus VoIP networks can leverage their INAP service investments, while enjoying the benefits of a converged VoIP network.
• Telecom Software Enterprises (TSE) provides software solutions and services for implementing "smart" call services for both circuit-switched and packet-based telephony. TSE's Net SmartConnect works with voice and data messaging solutions to provide real-time call connection between any circuit-switched or packet-switched communication device.
• Tundo enables a new IP-services delivery model by providing a highly scaleable and reliable hosted voice and media control platform for service providers. Tundo's platform is in use around the world by leading-edge companies that require innovative voice services delivered on a network-hosted basis.
• VINA Technologies is a leading developer of multiservice broadband access solutions that converge voice and data to the network edge. VINA's Integrator, Multiservice Xchange and eLink product families integrate various circuit- and packet-based broadband access technologies onto a single, open, and scaleable platform allowing service providers to smoothly migrate to the next generation network.
• Zenfinity provides convergence solutions to the service provider market. The company specializes in leading-edge optical, IP, and broadband technologies in the design, validation, integration and deployment of core, metro and access networks.

Today, Sonus also announced the restructuring of the OSPA into three tiers to streamline the growing program and offer partners greater interoperability choices. The three levels of the Alliance include Sonus Partners, Sonus Powered Partners and Sonus Platinum Partners. (See today's press release "Sonus Networks Broadens And Enhances Open Services Partner Alliance Program").

About Sonus' OSPA

Founded on the combination of Sonus' Open Services Partner Alliance (OSPA) Program and the INIP PoweredSM Partner Program from the acquisition of telecom technologies, inc., the OSPA has gained significant industry momentum, with membership of more than 100 leading independent vendors. The OSPA provides a framework that offers service providers end-to-end packet-based network solutions using best-of breed technologies and applications. The goal of the OSPA is to empower standards-based interoperability between applications, hardware vendors, and the Sonus product suite. An integral part of the Sonus OSPA, the Interoperability Laboratory is the first in the industry where product interoperability is verified, trial testing is performed, and complete solutions are ultimately produced. Additional information on the OSPA is available at http://ospa.sonusnet.com.

About Acterna

Acterna is the world's second largest communications test company, focused entirely on providing test and management equipment, software, systems and services. With presence in 80 countries, Acterna helps customers develop, install and maintain their optical, cable, data/IP, access and wireless networks. Acterna is the world leader in optical and cable networks. The company was formed by the May 2000 merger of TTC and Wavetek Wandel Goltermann, produces annualized revenue of more than $1 billion, and serves customers with 4,700 employees. Acterna is a subsidiary of Acterna Corporation (NASDAQ: ACTR). Information about Acterna can be found on the Web at www.acterna.com.

About ECI-NGTS

Next Generation Telephony Solutions is a leading provider of new voice infrastructure solutions and SIP based network and business applications. Consistent carrier-class quality and reliability are the hallmarks of NGTS products. ECI-NGTS leverages more than 20 years of global experience as the world's preeminent manufacturer of Digital Circuit Multiplication Equipment (DCME), and its historic strengths in providing exceptional quality in voice compression, FAX handling, signal classification, and DSP development in the design and manufacture of world-class packet-voice products. The Next Generation Telephony Solutions I-Gate 4000 and I-Gate 1000 are dense, scalable, flexible carrier-class Media Gateways employing the H.323, MGCP, H.248, and SIP protocols. NGTS solutions are deployed in 145 countries worldwide and serve both major carriers and emerging service providers at all stages of network implementation. The company has corporate headquarters in Petah Tikva, Israel and regional offices across Europe and Asia Pacific. In the USA the regional headquarters are in Herndon, VA. NGTS is a wholly owned subsidiary of ECI Telecom Ltd.

ECI Telecom Ltd is a provider of integrated network solutions for digital communications and data transmission systems. The Company designs, develops, manufactures, markets and supports end-to-end digital telecommunications solutions for today's new services and converging networks. The Company's products create bandwidth, maximize revenues for networking operators, expand capacity, improve performance and enable new revenue-producing services. In doing so, they enhance the capabilities of existing networks to support voice, data, video and multimedia services. ECI Telecom's equipment supports traffic in more than 500 service networks in over 145 countries.

About HearMe

HearMe (Nasdaq: HEAR) develops VoIP application technologies that deliver increased productivity and flexibility in communication via the next generation communications network. The Company's industry-leading PC-to-phone, phone-to-phone, and PC-to-PC VoIP application platform offers innovative technology and turnkey applications that dramatically simplify the process of bringing differentiated, enhanced communications services to market. Communications services supported or enhanced by HearMe technology include VoIP-based "instant" conferencing, VoIP Calling, and VoIP-enabled customer relationship management (CRM). HearMe has already licensed its VoIP application technologies to such leading companies as 3Com Corporation, QUALCOMM, Evoke, oCen Communications, and eshare Communications. Founded in 1995, HearMe is located in Mountain View, California, and can be reached at www.hearme.com or 650/429-3900.

About MIND

MIND (NASDAQ: MNDO) is a leading provider of Billing & Customer Care, Accounting and Management solutions for multiple IP services including Voice, Data, Content and Unified Messaging. MIND's billing and customer care solutions are servicing millions of subscribers worldwide. MIND's multiple IP services billing system provides ISPs, ITSPs and telcos with a real time solution for billing diverse IP services. MIND operates from its Israeli headquarters and provides sales and support services to its worldwide customer base from offices in the United States, Europe, China and Japan. For information about MIND and its products visit the company Web site: http://www.mindcti.com

About NetEffect Corporation

NetEffect bridges the gap between the introduction of next-generation communications applications with the infrastructure of clients' networks by designing, implementing and managing emerging networked applications and technologies. NetEffect's customer solutions for Fortune 1000 enterprises and service providers such as AT Solutions, BellSouth, IBM and WorldCom include Voice over IP, Interactive Call Center Technologies and Communications Infrastructure. Some of NetEffect's partners include Ace*comm, Amdahl, Cisco Systems and InfoVista. NetEffect employs NetAdvantageSM, a full life-cycle project management methodology, to deliver its services. NetEffect verifies and demonstrates its solutions in its NetCenter, a multimillion-dollar networking lab and training center. To take the Virtual Tour of the NetCenter and for further information, visit www.neteffectcorp.com.

About Switch Management

Switch Management Corporation is a telecom software company based in Oakland, California. In addition to Switch the Watchdog QoS monitor, SMC offers the popular WebCDR 100% web-based wholesale billing service. More information about SMC can be found at www.switchmanagement.com, or by calling 510-452-9200.

About Tango Telecom

Tango Telecom was formed in 1999 to create enhanced services for the competitive telecommunications market in both circuit and packet networks. The Tango team includes decades of cutting edge telecom services development and support experience from both equipment makers and telecom operators. Further information on the company and its products can be obtained from http://www.tango-tele.com

About Telecom Software Enterprises

Telecom Software Enterprises, LLC, based in Greenwood Village, Colorado provides software solutions and services for implementing "smart" call services for both circuit-switched and packet-based telephony. Telecom Software provides Converged, Advanced-Services applications that allow Service Providers to offer high-margin, converged (voice and data) services to their customers. These Advanced-Services applications give next-generation communications carriers market-facing applications that enable them to quickly implement compelling, high-margin offerings, acquire new customers, increase revenue (and profit) per customer, and reduce customer churn. Telecom Software, 5600 Quebec St., Suite 220A, Greenwood Village, Colorado, 80111, 303-770-3003, www.telecomse.com.

About Tundo Corporation

Tundo (pronounced tun-doo) is a pioneer in establishing a new era of voice and media communications over data networks. The company introduced the first truly open, carrier-grade IP telephony platform, the Network Telephony System (NTS)(TM) and Distributed Open Telephony Operating System (DOT-OS)(TM), in June 1999. The Tundo system enables a new IP services delivery model by providing a highly scaleable and reliable hosted voice and media control platform for service providers. Tundo's platform is in use across the globe by leading-edge companies that share a common vision of innovative voice services delivered on a network-hosted basis.

About VINA Technologies, Inc.

VINA Technologies creates broadband access solutions that allow communications service providers to extend the benefits of their core-network technology to the technologically underserved edge of the network. By converging voice and data on existing network infrastructures, service providers can quickly implement new value-added services, reduce operational costs and increase their revenue opportunities. With VINA solutions, service providers can protect their investment in their existing networks while migrating from circuit-switched to packet-switched communications. VINA solutions are protocol-independent enabling customers to migrate smoothly from existing technologies such as TDM to emerging technologies such as ATM or IP on one open, scalable platform. For more information about VINA Technologies, visit http://www.vina-tech.com. VINA Technologies' headquarters is located at 39745 Eureka, Newark, CA 94560; telephone: 1-888-774-VINA.

About Zenfinity, Inc.

Zenfinity, the "Masters of Intelligent Light"(TM), is promoting a Light Revolation for the service provider industry. Through its Light Revolation and optiLIGHT offerings, the company provides convergence solutions, delivering high-end solutions to service providers who offer integrated voice, video and data to their customers. Zenfinity is focused on delivering end-to-end service provider solutions that address every element of their infrastructure, emphasizing the latest in optical technologies. Zenfinity's solution offerings include Independent Network Assessments (INA) and Independent Verification and Validations (IV&V); security assessment and design; and integrated optical, core, access, services design and deployment. Additionally, the company provides staging, testing and configuration of integrated solutions in state-of-the-art laboratories.

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 (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' Prospectus, dated January 12, 2001, and associated Registration Statement on Form S-4, 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 its products, rapid technological and market change, integration risks relating to the acquisition of telecom technologies and manufacturing and sourcing risks.

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