DECEMBER 11, 2006, PETALUMA, CA—Calix today announced that recent reports from industry research firms broadbandtrends.com, Dell'Oro Group, and Infonetics Research name Calix as the growth leader in the North American DSL and worldwide GPON markets. Critical market measurements include:

1. broadbandtrends.com shows Calix DSL port shipments increasing 17% sequentially, top among all suppliers, while the overall DSL market declined by 34% sequentially. According to Teresa Mastrangelo, principal analyst with broadbandtrends.com, "A strong third quarter allowed Calix to expand market share and take the #1 position in the global broadband loop carrier market."
    
2. Dell'Oro Group has Calix showing the highest sequential growth rate among all North American DSL suppliers. Dell'Oro Group also places Calix as the #1 global supplier for gigabit passive optical network (GPON) optical line terminals (OLTs) and optical network terminals (ONTs).
    
3. 3.Infonetics Research places Calix #1 among North American DSL suppliers in terms of sequential growth. As it has throughout 2006, Infonetics also places Calix in the #1 market share position for North American multiservice access platform (MSAP) revenue. Said Jeff Heynen, directing analyst for broadband and IPTV for Infonetics Research, "Calix continues to turn in strong numbers, especially in the critical and rapidly-growing MSAP category."

Becoming the "broadband provider of choice" has become increasingly important for local exchange carriers (LECs) in their ongoing competition with cable operators. Among the 400 North American service providers relying on Calix for their access network requirements, fully 160 are delivering advanced video services to over 150,000 subscribers, dramatically enhancing their competitive posture. With DSL net additions exceeding those of cable for the eighth straight quarter (broadbandtrends.com), Calix is helping to shift the balance of power in favor of LECs.

"These reports confirm that Calix is well positioned to take advantage of market trends in the DSL and PON access markets," said John Colvin, Calix vice president of field operations. "Our highly integrated solutions enable service providers to rapidly and cost effectively deliver compelling IP-based service bundles over any combination of DSL and fiber access media."

About Calix
Calix is the largest telecom equipment supplier focused solely on access solutions for broadband service delivery. Service providers deploy Calix access systems to enable a rich set of information, communication, and entertainment services and to expand their revenue base beyond connectivity. Calix access innovation helps service providers transform their networks from circuit to packet, narrowband to broadband, and copper to fiber. Calix has deployed millions of ports and tens of thousand of systems into hundreds of service provider networks throughout North America. For more information, visit the Calix website at www.calix.com.

This press release may contain forward-looking statements that are based upon management's current expectations and involve risks and uncertainties. Forward-looking statements are based upon information available to us as of the date of this press 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. Actual results and the timing of events could differ materially from current expectations.

For additional information contact:

Jeannette Bitz / Engage PR / 510-748-8200 x207 / jbitz@engagepr.com