Culver City-based Fonality, a developer of business PBX phone systems based on the open source Asterisk PBX software, said today that it has named Dean Mansfield as the firm's new CEO. Mansfield replaces Chris Lyman, the firm's CEO and founder, who remains Chairman of the company's board. Manfield has previously served at such firms as NetSuite, Brocade Communications, Plumtree Software, and Mcafee. Lyman said the addition of Mansfield will help propel the firm to "the next level."