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                       SECURITIES AND EXCHANGE COMMISSION
                             WASHINGTON, D.C. 20549

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                                    FORM 8-K

                                 CURRENT REPORT

     PURSUANT TO SECTION 13 OR 15(d) OF THE SECURITIES EXCHANGE ACT OF 1934

                                 MARCH 13, 2006

                DATE OF REPORT (Date of earliest event reported)

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

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

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

                                 (978) 614-8100
              (Registrant's telephone number, including area code)

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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))

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     The information in this Current Report on Form 8-K and the exhibit attached
hereto shall not be deemed "filed" for purposes of Section 18 of the Securities
Exchange Act of 1934, as amended, or incorporated by reference in any filing
under the Securities Act of 1933, as amended, or the Exchange Act, except as
shall be expressly set forth by specific reference in such a filing.

ITEM 2.02.   RESULTS OF OPERATIONS AND FINANCIAL CONDITION.

     On March 13, 2006, Sonus Networks, Inc. issued a press release reporting
its financial results for the quarter and year ended December 31, 2005. A copy
of the press release is attached as Exhibit 99.1 hereto.

ITEM 9.01.   FINANCIAL STATEMENTS AND EXHIBITS.

       (d)   Exhibits

             The following exhibit relating to Item 2.02 shall be deemed to be
             furnished, and not filed:

             99.1    Press release of Sonus Networks, Inc. dated March 13, 2006
                     reporting financial results for the quarter and year ended
                     December 31, 2005.



                                    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: March 13, 2006                                 SONUS NETWORKS, INC.

                                                     By: /s/ Ellen Richstone
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                                                         Ellen Richstone
                                                         Chief Financial Officer



                                  EXHIBIT INDEX

99.1      Press release of Sonus  Networks,  Inc. dated March 13, 2006 reporting
          financial results for the quarter and year ended December 31, 2005.