- -------------------------------------------------------------------------------- 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 Date of report (Date of earliest event reported): October 13, 2000 SONUS NETWORKS, INC. (Exact name of registrant as specified in its charter) Delaware 000-30229 04-3387074 - -------------- ------------------------ ------------------- (State of (Commission File Number) (IRS Employer Incorporation) Identification No.) 5 Carlisle Road, Westford, MA 01886 --------------------------------------------------- (Address of principal executive offices) (Zip Code) (978) 692-8999 ---------------------------------------------------- (Registrant's telephone number, including area code) N/A ------------------------------------------------------------- (Former name or former address, if changed since last report) - -------------------------------------------------------------------------------

ITEM 5. OTHER EVENTS. Sonus Networks, Inc. (the "Company") effected a three-for-one stock split of its common stock, $0.001 par value per share ("Common Stock") in the form of a stock dividend paid on October 6, 2000 to those holders of record of the Company's Common Stock at the close of business on September 29, 2000. A copy of the press release issued by the Company announcing the three-for-one stock split is attached hereto as Exhibit 99.1 and is incorporated herein by reference. ITEM 7. EXHIBITS. EXHIBIT NUMBER DESCRIPTION - ------- ----------- 99.1 Press Release dated August 15, 2000 issued by Sonus Networks, Inc.

SIGNATURES 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: October 13, 2000 SONUS NETWORKS, INC. By: -------------------------------------- Stephen J. Nill, Chief Financial Officer, Vice President of Finance and Administration and Treasurer (authorized officer and principal financial and accounting officer) EXHIBIT INDEX EXHIBIT NUMBER DESCRIPTION - ------- ----------- 99.1 Press Release dated August 15, 2000 issued by Sonus Networks, Inc.

EXHIBIT 99.1 SONUS NETWORKS ANNOUNCES 3-FOR-1 STOCK SPLIT WESTFORD, MASS., AUGUST 15, 2000 - Sonus Networks (Nasdaq: SONS), a leading provider of voice infrastructure solutions for the new public network, today announced that the Company's board of directors has approved a three-for-one stock split of the Company's common stock. The stock split will be effected in the form of a stock dividend and stockholders of record at the close of business on September 29, 2000 will be entitled to two additional shares of common stock for each outstanding share of common stock held on that date. The additional shares are expected to be distributed by the Company's transfer agent on or about October 6, 2000 and the Company expects that its common stock will begin trading on a split-adjusted basis on October 9, 2000. ABOUT SONUS NETWORKS Sonus Networks, Inc. is a leading provider of voice infrastructure products for the new public network. Sonus' solutions enable service providers to deploy an integrated network capable of carrying both voice and data traffic, and to deliver a range of innovative, new services. The Sonus Open Services Architecture(TM) (OSA) and award-winning Packet Telephony suite cut the time-to-market for competitive new service products, allowing carriers and third-party developers to expand marketshare and build important new revenue streams. Its highly scalable products fully interoperate with and extend the life and utility of today's public network. Sonus embodies in its management and staff decades of experience in developing carrier-class voice, data and multimedia solutions for implementation in the world's largest networks. 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 for the quarter ended June 30, 2000, 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 our products, rapid technological and market change and manufacturing and sourcing risks. For more information, please contact: Beth Morrissey Sonus Networks 978-589-8579 bmorrissey@sonusnet.com # # #