Sonus Networks and Legatum Capital Reach Agreement

Sonus And Legatum Agree To Appoint Two New Independent Members To Expand
Sonus' Board

WESTFORD, Mass., Jan. 12 /PRNewswire-FirstCall/ -- Sonus Networks, Inc.
(Nasdaq: SONS), a market leader in IP communications infrastructure, and
Legatum Capital Limited, Sonus' largest stockholder which currently owns
approximately 65 million shares, or 25 percent of Sonus common stock, today
announced that they have entered into an agreement to add two new independent
members to Sonus' Board of Directors. The directors will be designated by
Legatum, subject to the terms of the agreement.

Following collaborative discussions between the Company and Legatum during the
past several months, the Board has approved a number of corporate governance
enhancements that complement Sonus' existing strong governance policies and
practices. These enhancements include:

-- Declassifying the Board, as previously announced in December 2008, by
the Company's 2011 Annual Meeting of Stockholders;
-- Separating the roles of chairman and chief executive officer; and
-- Forming an ad hoc Corporate Development and Investment Committee to
focus on uses of the Company's cash, tax planning, strategic
acquisitions, mergers and joint ventures, with the objective of
enhancing stockholder value.

Under the agreement, Legatum will refrain from putting forth proposals or
taking actions in connection with the Company's 2009 Annual Meeting of
Stockholders.

"Sonus' Board is committed to the highest standards of corporate governance
and today's announcement, coupled with our recent governance enhancements, is
the latest positive step forward, demonstrating our ongoing commitment to
enhancing stockholder value," said Richard Nottenburg, president and chief
executive officer of Sonus Networks. "Legatum is an important partner and
investor with a clear commitment to our long-term vision and success. We have
listened to their recommendations and are pleased to have reached an agreement
that will benefit all our stakeholders. Both the Board and management welcome
the new perspectives and insights that the new directors will bring."

"Legatum remains committed to supporting the Board and Management's efforts to
drive long-term profitable growth and deliver shareholder value," said Mark
Stoleson, president of Legatum Capital Limited. "We are encouraged that the
constructive dialogue we have enjoyed with Dr. Nottenburg and the Sonus Board
has resulted in a range of initiatives that we are confident will better
position Sonus to realize its long-term potential and enhance value for all
Sonus stakeholders."

The complete agreement will be included as an exhibit in the Company's Form
8-K to be filed with the Securities and Exchange Commission.

About Legatum Capital Limited
Legatum is a privately owned international investment organization, whose
primary focus is commercial investment in international equities and financial
securities, and which also applies its investor's expertise to a long-standing
involvement in the sustainable development of communities around the globe.
The Legatum Group was founded in December 2006 following the demerger of the
Sovereign Global group of companies ("Sovereign") which provided capital to
companies and governments in various industry sectors worldwide since 1986.

The Group is composed of a number of divisions: Legatum Capital, Legatum
Global Development ("LGD"); the Legatum Institute, which publishes the annual
Legatum Prosperity Index; and the Legatum Center at Massachusetts Institute of
Technology ("MIT"). Additional information is available at www.legatum.com.

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.

For more information, please contact:

SONUS:
Media Relations:
Lucy Millington Matthew Sherman / Tim Lynch
978-614-8240 212-355-4449
lmillington@sonusnet.com msherman@joelefrank.com
tlynch@joelefrank.com

Investor Relations:
David Roy / Karin Cellupica
978-614-8253 / 978-614-8615
droy@sonusnet.com
kcellupica@sonusnet.com

LEGATUM:
Hamish Banks
+971 4 317 5800
Hamish.Banks@legatum.com

SONUS SAFE HARBOR:
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.

SOURCE Sonus Networks, Inc.

Media Relations: Lucy Millington of Sonus, 1-978-614-8240,
lmillington@sonusnet.com, or Matthew Sherman, msherman@joelefrank.com, or Tim
Lynch, tlynch@joelefrank.com, both at +1-212-355-4449, for Sonus; Investor
Relations: David Roy +1-978-614-8253, droy@sonusnet.com, or Karin Cellupica,
+1-978-614-8615, kcellupica@sonusnet.com, both of Sonus; or Hamish Banks of
Legatum, +971-4-317-5800, Hamish.Banks@legatum.com