Sonus Networks and Atreus Systems Partner to Simplify the Delivery of Hosted Business VoIP Services

Sonus Networks and Atreus Systems Partner to Simplify
the Delivery of Hosted Business VoIP Services

Partnership Helps Carriers to Evolve VoIP Offers to Leverage IMS-based Capabilities

San Jose, CA and Ottawa, ON, March 15, 2006 — Spring VON 2006 (Booth #517), Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier of service provider voice over IP (VoIP) infrastructure solutions, and Atreus Systems™ (Booth #1133), the premier supplier of provisioning software for IMS, VoIP and advanced IP service bundles, today announced a partnership that will enable service providers to reduce operating costs and speed the delivery of hosted VoIP services. As a member of Sonus’ Open Service Partner Alliance (OSPA), Atreus will partner with Sonus to deliver a solution that empowers carriers to generate new revenue streams by simplifying the delivery of a suite of value-added consumer and business voice services, including Hosted PBX, business trunking (Integrated Access), conferencing, and voice VPN services.

The joint solution has been selected by one of the largest carriers in North America as the foundation for its next generation voice network. By deploying Atreus’ automated provisioning and customer self-management software over Sonus’ industry-leading IP Multimedia Subsystem (IMS)-ready architecture, service providers can take advantage of a complete solution that ensures flexibility, reliability and the rapid delivery of bundled VoIP offerings. The joint solution automates the processes to quickly turn up hosted voice, messaging, conferencing and voice VPN capabilities for residential and enterprise customers. The key features will:

“This partnership enables Sonus Global Services to extend its capabilities with a fully integrated service delivery platform. The solution allows carriers across the globe to increase revenue and contribution per customer by leveraging their existing investments to support VoIP and incorporate high-value business applications,” said Steve Edwards, Chief Marketing Officer, Sonus Networks. “Together, we’re committed to offering our customers flexible, carrier-grade VoIP solutions today, while supporting providers’ future requirements for converged voice-video-data services.”

“Sonus’ leadership in next-generation packet voice technologies, coupled with Atreus’ proven expertise in automated service provisioning, enables our carrier customers to enhance their business through the rapid deployment of feature-rich consumer and business VoIP bundles,” said Len Castelli, Vice President of Business Development. “This strategic partnership will help service providers differentiate their products and win business with competitive new voice offerings.”

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 comprehensive IP Multimedia Subsystem (IMS) solution, Sonus addresses the full range of carrier applications, including residential and business voice services, wireless voice and multimedia, trunking and tandem switching, carrier interconnection and enhanced services. Sonus' voice infrastructure solutions are deployed in service provider networks worldwide. Founded in 1997, Sonus is headquartered in Chelmsford, Massachusetts. Additional information on Sonus is available at www.sonusnet.com.

About Atreus Systems
Atreus Systems™ is the premier supplier of provisioning software for IMS, VoIP and advanced IP service bundles. Atreus leads the market with award winning products and is the vendor of choice for the delivery of advanced IP services by leading providers, including Telus, Aliant, Voila IP and Xspedius. Atreus has formed strategic partnerships with BroadSoft, Ericsson, Level 3, and SONUS, delivering carrier-class reliability and scalability for IMS, VoIP, and advanced IP bundles. For more information, visit atreus-systems.com.