International Next Generation Network Provider Interoute Selects Sonus Networks for Multi-Million Dollar Network Expansion

International Next Generation Network Provider Interoute Selects Sonus Networks for Multi-Million Dollar Network Expansion

May 10, 2006

Interoute Leverages Sonus' IMS Solution to Support Increased Demand for Leading VoIP Services

    SWINDON, England, May 10 /Xinhua-PRNewswire-FirstCall/
-- Sonus Networks, Inc. (Nasdaq: SONS), a leading supplier
of service provider Voice over IP (VoIP) infrastructure
solutions, announced today that Interoute, owner and
operator of one of Europe's most advanced
telecommunications networks, has selected Sonus Networks'
IMS (IP Multimedia Subsystem)-ready network infrastructure
solutions to support the multimillion dollar expansion of
its IP-based voice network into several major markets,
including Madrid, Spain and Milan, Italy.  The Sonus
solution offers Interoute the authentication and security
features necessary to support its carrier-class Virtual
Voice Network (VVN) service and Arena, Interoute's
commission-free voice exchange, which gives carriers the
ability to exchange traffic securely and flexibly with
other operators around the world.  Sonus' IMS-ready,
standards-based platform was selected because it provides
Interoute with the scalability and reliability necessary to
meet the growing demand for the company's enhanced voice
services. 

    "For years Sonus and Interoute have partnered to
develop one of Europe's most sophisticated VoIP networks.
Interoute has been a pioneer in the rollout of high value
IP-based services, such as iSip and Arena, and continues to
invest in its Sonus-based network to differentiate itself as
one of the premier providers of VoIP services in the
region," said Hassan Ahmed, chairman and CEO, Sonus
Networks. "As Interoute further extends its presence
in cities throughout Europe, Sonus is uniquely positioned
to help them meet their growth objectives and support the
increasing amount of traffic being carried on their
network."

    "We selected the Sonus platform because, from day
one, we recognized the flexibility that its distributed,
standards-based architecture would deliver," said
Matthew Finnie, CTO Interoute.  "The Sonus platform
utilizes sound engineering principles fundamentally in line
with the emerging IMS standards, which enables the
development of standards-based services such as enhanced
content aggregation and delivery. A standards-based
architecture is essential for the shared infrastructure
products that Interoute offers to our customers." 

    Interoute has been a Sonus customer since 2002 and has
deployed the complete Sonus architecture, including the
GSX9000(TM) Open Services Switch, the PSX(TM) Call Routing
Server and the Sonus Insight(TM) Management System in
cities across Europe and North America. 

    About Interoute

    Interoute is Europe's fastest growing telecoms provider
and owner operator of the continent's most advanced and
densely connected voice and data network.  It delivers
intelligent, customer-controlled network services to a
diverse range of businesses including carriers, mobile
operators, service providers, enterprise customers and
governments.  With established operations throughout
mainland Europe and North America, Interoute also owns and
operates long-haul and dense city networks throughout
Europe's major business centers.

    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 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, dated March
14, 2006 and Quarterly Report on Form 10-Q, dated May 8,
2006, both 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 impact of material
weaknesses in our disclosure controls and procedures and
our internal control over financial reporting on our
ability to report our financial results timely and
accurately; the unpredictability of our quarterly financial
results; risks associated with our international expansion
and growth; consolidation in the telecommunications
industry; and potential costs resulting from pending
securities litigation against the company.  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, Inc.
 Sonus GSX9000 Open Services Switch, PSX Call Routing
Server, SGX Signaling Gateway, and the Sonus Insight
Management System are trademarks of Sonus Networks, Inc. 
All other company and product names may be trademarks of
the respective companies with which they are associated.

    For more information, please contact:

     Investor Relations
     Jocelyn Philbrook
     Tel:   [phone]
     Email: [e-mail]

     Media Relations 
     Sarah McAuley 
     Tel:   [phone]
     Email:[e-mail]

     Media Relations EMEA 
     Tom Cheesewright
     Tel:   [phone]
     Email: [e-mail]

SOURCE  Sonus Networks, Inc. 

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