• Chief Scientist, Network Technologies and Corporate Systems, Verizon (11/2012 to 2/2013)
  • Chief Scientist, Verizon Services Operations, Verizon (11/2005 to 11/2012)
  • Chief Scientist, Verizon Information Technology, Verizon (11/2000 to 11/2005)
  • Senior Technologist, Verizon Technology Organization (7/2000 to 11/2000)
  • GTE and Bell Atlantic merged to form Verizon Communications June 30, 2000
  • Chief Scientist, GTE Laboratories (8/1994 to 7/2000)
  • Manager, Distributed Object Computing Department, GTE Laboratories (08/1987 to 08/1994)
  • Research Director, Research and Systems Division, Computer Corporation of America, (01/1983 – 07/1987)
  • Assistant Professor of Information Systems Management and Computer Science, University of Maryland (1979 – 1982)
  • Assistant Professor of Computer Science, University of Toronto, Canada (1978)
  • Visiting Professor, Fachbereich Informatik, Universit√§t Hamburg, Germany (1978)
  • Visiting Professor, Depto. de Informatica Pontifical Universidade Catolica, Rio de Janeiro, Brazil (1976)