EXHIBIT 99.1

FOR IMMEDIATE RELEASE

For more information, please contact:

Investor Relations                                   Public Relations
Jocelyn Lynds                                        Beth Morrissey
(978) 589-8672                                       (978) 589-8579
jlynds@sonusnet.com                                  bmorrissey@sonusnet.com

                 SONUS NETWORKS PROVIDES ESTIMATED FIRST QUARTER
                                FINANCIAL RESULTS

WESTFORD, MASS., MARCH 27, 2002 - Sonus Networks (Nasdaq: SONS), a leading
provider of voice infrastructure solutions for the new public network, today
provided its estimated financial results for the first quarter of fiscal year
2002.

Reflecting the continued weakness in the telecommunications market, the Company
expects revenues for the first quarter ending March 31, 2002 to be approximately
$21 million. Based on these revenues, the Company expects to report an adjusted
net loss for the quarter of approximately $0.08 per share, excluding
restructuring and non-recurring charges, amortization of goodwill and purchased
intangibles and stock-based compensation. The Company also expects to record a
$5 million to $10 million charge in the quarter, associated with excess
inventory.

"The further deterioration in the U.S. telecom industry, for both emerging
carriers and even the largest service providers, has led to a decline in our
revenues for first the quarter," said Hassan Ahmed, president and CEO, Sonus
Networks. "We continue to manage our business with precision as we work through
these near-term challenges, and we remain focused on our financial metrics.
Looking forward, based on the opportunities that we are currently participating
in, we are very confident of the future prospects for Sonus."

                     CONFERENCE CALL AND WEBCAST INFORMATION

Sonus Networks will host a conference call today, March 27, 2002, beginning at
5:00 p.m. Eastern time. To listen via telephone, the dial-in number is (800)
252-9521 or (212) 346-6438. Sonus will also host a live webcast of the
conference call. To access the webcast, visit www.sonusnet.com, Corporate,
Investor Relations. A telephone playback of the call will be available following
the conference and can be accessed by calling (800) 633-8284 or (858) 812-6440.
The reservation number for the replay is 20468726. The telephone playback will
be available through Friday, April 5, 2002. The webcast will be also available
on the Sonus Networks Investor Relations site through Friday, April 5, 2002. To
access the replay of the webcast, visit www.sonusnet.com, Corporate, Investor
Relations.
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ABOUT SONUS NETWORKS
Sonus Networks, Inc., is a leading provider of packet voice infrastructure
products for the new public network. With its Open Services Architecture(TM)
(OSA), Sonus delivers end-to-end solutions addressing a full range of carrier
applications, including trunking, residential access and Centrex, tandem
switching, and IP voice termination, as well as enhanced services. Sonus'
award-winning voice infrastructure solutions, including media gateways,
softswitches and network management systems, are deployed in service provider
networks worldwide. 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' Quarterly Report
on Form 10-Q, dated November 14, 2001, 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 and manufacturing and sourcing risks.

                                      # # #
OPEN SERVICES ARCHITECTURE IS A TRADEMARK OF SONUS NETWORKS. ALL OTHER
TRADEMARKS, SERVICE MARKS, REGISTERED TRADEMARKS, OR REGISTERED SERVICE MARKS
ARE THE PROPERTY OF THEIR RESPECTIVE OWNERS.