|Founded||7 August 1997|
|Raymond P. Dolan (President and CEO)|
Number of employees
|more than 3000|
Sonus was founded on August 7, 1997, and went public on May 25, 2000.
In January 2001, Sonus acquired Anousheh Ansari's firm Telecom Technologies, Inc., in an all-stock deal. Sonus subsequently integrated TTI's softswitch technology INtelligentIP into its own packet telephony suite.
In March 2004, Sonus Networks announced that it was likely to restate its 2002 and 2003 results because revenue was booked during the wrong periods. In June, 2004, Sonus Networks announced to restate its historical financial statements for 2001, 2002 and the first three quarters of fiscal year 2003, based on the status of its ongoing review.
In August 2012, Sonus acquired Network Equipment Technologies, Inc., for $1.35 per share, or approximately $42 million. The acquisition complemented their existing SBC line with the NET UX series for SIP Trunking and SIP-based UC. 
On Dec 13, 2013, Sonus Networks, Inc. and Performance Technologies Inc entered into a definitive merger agreement, under which Sonus will acquire PT for $3.75 per share in cash, or approximately $30 million.
- "Form 8-K current report / Sonus Networks, Inc. / Item 2. Acquisition or Disposition of Assets". SEC. 2001-02-02. Retrieved 2015-03-22.
- "Sonus Networks Completes Acquisition of Telecom Technologies". Sonus Networks. 2001-01-18. Retrieved 2015-03-22.
- "Sonus Networks to Restate Financial Results".
- "Sonus Networks Announces Definitive Agreement to Acquire Network Equipment Technologies".
- "Sonus Networks Announces Definitive Agreement to Acquire Performance Technologies, Inc.".