SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549


                                    FORM 8-K

                                 CURRENT REPORT

     Pursuant to Section 13 or 15(d) of the Securities Exchange Act of 1934

                                  June 8, 2005

                Date of Report (Date of earliest event reported)


                              SONUS NETWORKS, INC.
             (Exact Name of Registrant as Specified in its Charter)



         DELAWARE                      000-30229             04-3387074
        -----------                    ---------             ----------
(State or Other Jurisdiction   (Commission File Number)    (IRS Employer
  of Incorporation)                                       Identification No.)

                250 APOLLO DRIVE, CHELMSFORD, MASSACHUSETTS 01824
               (Address of Principal Executive Offices) (Zip Code)

                                 (978) 614-8100

              (Registrant's telephone number, including area code)


Check  the  appropriate  box  below  if the  Form  8-K  filing  is  intended  to
simultaneously  satisfy the filing obligation of the registrant under any of the
following provisions (see General Instruction A.2. below):

|_|  Written  communications  pursuant to Rule 425 under the  Securities Act (17
     CFR 230.425)

|_|  Soliciting  material pursuant to Rule 14a-12 under the Exchange Act (17 CFR
     240.14a-12)

|_|  Pre-commencement   communications  pursuant  to  Rule  14d-2(b)  under  the
     Exchange Act (17 CFR 240.14d-2(b))

|_|  Pre-commencement   communications  pursuant  to  Rule  13e-4(c)  under  the
     Exchange Act (17 CFR 240.13e-4(c))


Item 8.01. Other Events. On June 8, 2005, Sonus Networks, Inc. issued a press release reporting the termination of an SEC investigation. A copy of the press release is attached as Exhibit 99.1 hereto.

SIGNATURE Pursuant to the requirements of the Securities Exchange Act of 1934, the Registrant has duly caused this report to be signed on its behalf by the undersigned hereunto duly authorized. Date: June 8, 2005 SONUS NETWORKS, INC. By: /s/ Ellen Richstone ------------------------- Ellen Richstone Chief Financial Officer

Exhibit Index 99.1 Press release of Sonus Networks, Inc. dated June 8, 2005 reporting the termination of an SEC investigation.

                                                                    Exhibit 99.1


           Sonus Networks Announces Termination of SEC Investigation


    CHELMSFORD, Mass.--(BUSINESS WIRE)--June 8, 2005--Sonus Networks
(Nasdaq: SONS), a leading supplier of service provider voice over IP
(VoIP) infrastructure solutions, announced that it has received
written notification from the Securities and Exchange Commission
regarding the formal inquiry that the SEC undertook in connection with
the Company's previously announced independent investigation of its
financial reporting. The SEC has notified the Company that its
investigation has been terminated and that no enforcement action has
been recommended.

    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 Open Services Architecture(TM) (OSA), Sonus delivers
end-to-end solutions addressing a full range of carrier applications,
including trunking and tandem switching, residential and business
access, network border switching and enhanced services. Sonus' 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 Chelmsford,
Massachusetts. Additional information on Sonus is available at
http://www.sonusnet.com.

    Sonus is a registered trademark of Sonus Networks. Open Services
Architecture, GSX9000 and Insignus are trademarks of Sonus Networks.
All other trademarks, service marks, registered trademarks, or
registered service marks are the property of their respective owners.


    CONTACT: Investor Relations:
             Jocelyn Philbrook, 978-614-8672
             jphilbrook@sonusnet.com
             or
             Media Relations:
             Laureen McGowan, 617-275-6515
             lmcgowan@greenoughcom.com