Exhibit 99.1

            SONUS NETWORKS RECEIVES EXPECTED NASDAQ NOTICE RELATED TO
                       LATE FILING OF Q2 FY2006 FORM 10-Q

    CHELMSFORD, Mass., Aug. 16 /PRNewswire-FirstCall/ -- Sonus Networks, Inc.
(Nasdaq: SONS) announced that the Company received, as expected, a NASDAQ Staff
Determination letter on August 14, 2006, indicating that the Company is not in
compliance with the NASDAQ continued listing requirements set forth in
Marketplace Rule 4310(c) (14). The Determination letter relates to the delay
previously announced by the Company in the filing of its Form 10-Q for the
fiscal quarter ended June 30, 2006.

    Sonus Networks will request a continued listing hearing with the NASDAQ
Listing Qualifications Panel. Pending a decision by the Panel, the Company's
securities will remain listed on The NASDAQ Stock Market.

    As announced on August 7, 2006, the Company is voluntarily reviewing the
processes by which it has historically issued and accounted for employee stock
options. The Company will not be in a position to publish its Form 10-Q for the
quarter ended June 30, 2006 until the review has been completed and the Company
determines if any non-cash, stock-based compensation adjustments are necessary
and the impact, if any, to its financial statements. The Company is focused on
completing this voluntary review as soon as possible, but has not provided an
anticipated completion date at this time.

    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' Quarterly Report on Form 10-Q, dated May 8, 2006, filed with
the Securities and Exchange Commission, which identifies 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 and uncertainties associated with the Company's announced review of its
historical stock option grants and accounting, including any potential impact of
the Company's financial statements or results, the Company's inability to timely
report with the Securities and Exchange Commission, the Company's potential
inability to meet NASDAQ requirements for continued listing, whether the NASDAQ
Panel will grant a request for continued listing, potential investigations or
litigation arising out of the review or any restatement; 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. 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:               US Media Relations:
    Jocelyn Philbrook                 Sarah McAuley
    978-614-8672                      212-699-1836
    jphilbrook@sonusnet.com           smcauley@sonusnet.com