WESTFORD, Massachusetts and STAINES, England, February 18 /PRNewswire/ --

- Sonus Networks Part Of PathFinder Programme To Foster Interoperability

Sonus Networks (Nasdaq: SONS), a market leader in IP communications
infrastructure, today announced that its solutions for wireless carriers have
been certified as part of PathFinder, the GSMA-managed service operated by
NeuStar. The PathFinder initiative is dedicated to the simple delivery of
IP-based services to fixed and mobile networks, reducing the cost and
complexity of providing innovative new services.

PathFinder is based on Carrier ENUM technology, facilitating an
interoperable, industry-wide solution which enables the routing of global IP
service interconnect traffic. The service acts as a central directory where
operators share IP and fixed-line addresses to allow swift and cost-effective
routing of packet voice, instant messaging (IM), multimedia services, email
and video. By assisting the linking of an IP address to a phone number for
mobile devices, fixed-line phones and IP devices, the delivery of IP-based
services is made easier.

"As a PathFinder Industry Partner, Sonus Networks is pleased to be part
of an important initiative which seeks to promote the introduction of new
services and revenue streams," said Shailin Sehgal, vice president of
marketing and product management at Sonus Networks. "Sonus is committed to
building interoperable solutions to help carriers migrate seamlessly from
legacy systems to their next generation network. Protecting return on
previous investments while positioning for future subscriber growth and new
services is more important than ever for carriers in the current economic
climate."

"Sonus Networks is an important addition to the community of next
generation network providers," added Steve Edwards, senior vice president of
Converged Addressing at NeuStar. "As the PathFinder service moves into
production, it is key to carriers planning their networks that leading
industry players such as Sonus are certified interoperable with PathFinder."

About NeuStar

NeuStar (NYSE: NSR) provides market-leading and innovative services that
enable trusted communication across networks, applications, and enterprises
around the world. For more information, visit www.neustar.biz.

About Sonus Networks

Sonus Networks, Inc. is a market leader in IP communications
infrastructure 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 Westford, 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 Item 1A "Risk
Factors" of our Annual Report on Form 10-K for the year ended December 31,
2007 and all subsequent Quarterly Reports on Form 10-Q, 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 Company's ability to align its cost structure with market
conditions, 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 and uncertainties associated with
the Company's restatement of its historical stock option granting practices
and accounting including regulatory actions; actions that may be taken by
significant shareholders; risks associated with our international expansion;
and the impact the current global financial market conditions may have on the
telecommunications industry. 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, except as required by law.

Sonus is a registered trademark 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:

    US Media Contact:                 EMEA Media Contact:
    Shannon Breen                     Lauren Bishop/Lucia Barbato 
    +1-781-487-4607                   +44(0)20-7107-2479/2480
    sonus@racepointgroup.com          sonus.team@catalysis.co.uk