Southwest Telephone Exchange selects Calix for Broadband Stimulus Initiative

Iowa company to use GPON across C7 and E7 to deliver advanced broadband services

PETALUMA, CA — —Calix, Inc. (NYSE: CALX) today announced that Broadband Stimulus award winner Southwest Telephone Exchange, a subsidiary of Interstate 35 Telephone Company, has selected the Calix Unified Access portfolio to deliver advanced broadband services over fiber to residences, businesses, and community institutions in the communities of Imogene, Emerson, and Henderson, Iowa and their surrounding rural areas. The network, designed by HunTel Engineering, will consist of a 10 gigabit per second (Gbps) Ethernet transport ring connecting multiple Calix platforms – the Calix C7 Multiservice Access Platform (MSAP) and the E7 Ethernet Service Access Platform (ESAP). Each residence, business, and community institution will receive services via gigabit passive optical network (GPON) technology terminating on a variety of Calix 700GE optical network terminals (ONTs). The award given to Southwest Telephone Exchange, which includes plant engineering, materials, labor, and other costs, including access equipment, totals $6 million, including a $4.1 million grant and a $1.9 million loan.

“Building a robust broadband infrastructure is critical to creating jobs and economic opportunities in our communities in southwest Iowa,” said Bryan Nelson, plant manager at Southwest Telephone Exchange’s parent company Interstate 35 Telephone. “This Stimulus award will be transformational to our communities, providing over 1600 residents and businesses what we believe will be one of the most advanced broadband networks in the nation. We look forward to working with our long-time partner Calix to deploy this state-of-the-art network, bringing superior broadband services to the local residents and laying a strong foundation for economic development throughout the region.”

“By leveraging powerful Calix GPON solutions capable of delivering 1 Gbps to local homes and/or businesses, these three towns in rural southwest Iowa will join the ranks of the most connected cities in North America,” said John Colvin, vice president of field operations at Calix. “We are proud to have been chosen by Southwest Telephone Exchange as access vendor to this transformational initiative, and look forward to working with the company to ensure that their customers reap the benefits of a world-class fiber access network infrastructure.”

With today’s announcement, aggregate Calix vendor selections by Broadband Stimulus winners for “last mile” BIP awards has now reached nineteen different projects representing approximately $216 million in Stimulus-related grants, loans, and private investment for plant engineering, materials, labor, and other costs, including access equipment.

About Calix

Calix is a leading North American provider of broadband communications access systems and software for fiber- and copper- based network architectures that enable communications service providers to connect to their residential and business subscribers. Calix has shipped over seven million ports of its Unified Access Infrastructure portfolio to more than 600 North American and international customers, whose networks serve over 40 million subscriber lines in total.

This press release may contain forward-looking statements that are based upon management’s current expectations and are inherently uncertain. Forward-looking statements are based upon information available to us as of the date of this release and we assume no obligation to revise or update any such forward-looking statement to reflect any event or circumstance after the date of this release, except as required by law. Actual results and the timing of events could differ materially from current expectations, based on risks and uncertainties affecting the Company’s business. The reader is cautioned not to unduly rely on the forward-looking statements contained in this press release. Additional information on potential factors that could affect Calix’s results and other risks and uncertainties are detailed in its report on Form 10-Q for the fiscal quarter ended September 25, 2010, filed with the SEC on October 22, 2010, available at http://www.sec.gov.