Standing in front of his southwest Santa Rosa office building on Thursday, Dane Jasper pointed out three buried utility boxes, their labels etched into the tops: AT&T, Comcast and Sonic, the telecom company Jasper co-founded 19 years ago.

"It's pretty exciting," the Sonic.net CEO said. "We're in the mix."

The Santa Rosa-based Internet provider has been laying 3 1/2 miles of fiber-optic cables under the office park south of Sebastopol Road. It will soon offer businesses Internet speeds of up to 1 gigabit per second, about 100 times faster than most household Internet connections.

This is the company's second fiber venture after stringing cables on telephone poles across Sebastopol last year and offering the latest generation of high-speed Internet direct to homes.

For the Santa Rosa office park, Sonic invested in drilling equipment and hired a construction crew as it looks to expand its fiber footprint.

"Fiber is very exciting to us," Jasper said. "It allows us to deliver much higher speeds in a cost-effective way. It has no limits."

When the first cables are in place in two months, Sonic will offer businesses the gigabit Internet connection bundled with a hosted PBX service, essentially a phone line hosted on the company's system, for $40 a month. Santa Rosa businesses within the fiber footprint have shown early interest.

Visual effects company Factory VFX, which is along the fiber cable, exchanges large movie files with Hollywood studios and craves more bandwidth, CEO Eric Christensen said.

"I think this is fantastic," he said. "It's going to be good for us. I'm counting the days until my Comcast contract expires."

Sonic's core business is copper broadband, and the company has 50,000 accounts in the Bay Area, Sacramento and Los Angeles. It provides Internet service to 38 percent of households in Sebastopol, its most concentrated market. In Santa Rosa, 11 percent of households are customers. Sixty percent of its customers are residential users, with the rest mostly small businesses.

The company has 200 employees and has doubled in size in the past three years, Jasper said. He declined to release current revenues for the company, which generated $21 million in sales in 2009.

Sonic's future is in fiber, Jasper said. The company plans to start wiring business parks along the Highway 101 corridor, with the Airport Business Center north of Santa Rosa next.

The hair-thin glass wires that can produce blazing fast Internet speeds are replacing copper networks around the country. Most of the large Internet companies offer fiber products, such as Verizon's FiOS and AT&T's U-verse, though at speeds less than 1 gbps.

Jasper said the speed and price of Sonic's fiber Internet service could be game-changing for Santa Rosa business customers.

"Gigabit fiber to the business at this rate is unique," he said. "(It) will have a real effect on the business located within this new fiber footprint."

Sonic is planning to eventually roll out fiber service to homes in the markets it serves, Jasper said. The company was not ready to announce its timetable Thursday.

"It is a learning process. It is an investment process. It takes time. In the long run, we want to reach as many consumers and businesses as we can," Jasper said.