There is no more innovative VoIP company than Digium. The maker of the Asterisk open-source VoIP platform provides products that deliver high-end feature sets and strong ROI for SMB customers. But you need more than innovative technology to take on a rival like Cisco Systems; you need a great hard-driving sales channel. Windham gets it. And he has already challenged Cisco in the value networking segment as the president and chief operating officer of Adtran, experience he's sure to draw on as he brings high-margin products to the VoIP channel.