ShoreTel, a Sunnyvale, Calif, provider of Internet telephone systems for companies, has filed an initial public offering to sell up to $85 million in common stock.

The company’s revenue is on the low side for an IPO. It was $20.4 million for the three months ended Sept. 30, however, that’s about double the revenue for the same period the year before, suggesting strong growth.

ShoreTel raised some $107 million from venture firms like Crosspoint Venture Partners, Focus Ventures, Foundation Capital, Globespan Capital Partners, J.P. Morgan Chase, Lehman Brothers, Matrix Partners and Norwest Venture Partners.