Exhibit 32.1
CERTIFICATION OF CHIEF EXECUTIVE OFFICER
PURSUANT TO 18 U.S.C. SECTION 1350,
AS ADOPTED PURSUANT TO SECTION 906
OF THE SARBANES-OXLEY ACT OF 2002
In connection with the Annual Report on Form 10-K for the fiscal year ended December 31, 2011 of Calix, Inc. (the “Company”) as filed with the Securities and Exchange Commission on the date hereof (the “Report”), I, Carl Russo, Chief Executive Officer of the Company, certify, pursuant to 18 U.S.C. Section 1350, as adopted pursuant to Section 906 of the Sarbanes-Oxley Act of 2002, that:
| 1. | The Report fully complies with the requirements of Section 13(a) or Section 15(d) of the Securities Exchange Act of 1934, as amended; and |
| 2. | The information contained in the Report fairly presents, in all material respects, the financial condition and results of operations of the Company. |
| /s/ Carl Russo |
| Carl Russo |
| Chief Executive Officer |
Date: February 23, 2012
This certification accompanies the Form 10-K to which it relates, is not deemed filed with the Securities and Exchange Commission and is not to be incorporated by reference into any filing of Calix, Inc. under the Securities Act of 1933, as amended, or the Securities Exchange Act of 1934, as amended (whether made before or after the date of the Form 10-K), irrespective of any general incorporation language contained in such filing.