Thanks to Jonathan Rosenberg, the Internet could usurp the role of the old-fashioned phone network. The key is a set of computer instructions that make it practical for the Internet to carry not just data but two-way telephone calls, teleconferences and pages. This “session initiation protocol” also supports new-fangled connections like instant messaging and “presence,” which tracks who is available online at any given moment. Rosenberg produced the protocol with Columbia University telecom expert Henning Schulzrinne while working toward his doctorate at Columbia and overseeing video compression research at Bell Labs. The telecom industry heralded the protocol, and the Third-Generation Partnership Project, a high-profile colloquium for setting wireless standards, adopted it in 2000.As chief scientist at East Hanover, NJ, startup dynamicsoft, Rosenberg has since been cooking up a suite of related software that would enable wireless phones to download voice, text and video and would let company Web sites provide voice links to live customer service representatives.