In the midst of an effort to transform from a stodgy hardware business to more of a software company, Cisco has just lost one of its top executives spurring the transition.

Cisco said on Tuesday said that Rowan Trollope, senior vice president and head of the emerging Internet of Things division, is leaving to become CEO of Five9, which provides cloud software for contact centers.

Trollope was one of CEO Chuck Robbins' leading lieutenants, also running the collaboration technology group, which includes Spark and WebEx. The change is effective on May 3, Cisco said in a statement.