David Hanes, CCIE No. 3491, is currently a senior engineer that specializes in the training, design, and troubleshooting of fax technologies for the Cisco Customer Assurance Engineering (CAE) group. Since joining Cisco in 1997, he has worked as a Technical Assistance Center (TAC) engineer for the WAN, WAN Switching, and Multiservice Voice teams, a team lead for the Multiservice Voice team, and an Escalation Engineer covering a variety of voice and fax technologies. David has been troubleshooting escalated issues in Cisco customer networks around the world while delivering training, design assistance, and writing documentation for fellow Cisco engineers. Prior to working at Cisco, David was a Systems Engineer for Sprint where he gained his first computer networking experience working on frame relay and X.25. He holds a B.S. in Electrical Engineering from North Carolina State University.