Ruixi Yuan is a network researcher focusing on high-speed networking and security. He was the architect of Genuity's VPN Advantage Service and served as its product manager. In addition, he has conducted research and development in computer and communication networks at NEC, GTE Laboratories, and BBN Technologies. W. Timothy Strayer is a senior scientist at BBN Technologies where he conducts research on network protocols, routing infrastructures, computer security, and network management and monitoring systems for VPNs. Prior to BBN, he was a senior network researcher at Sandia National Laboratories. He co-authored the book, XTP: The Xpress Transfer Protocol (Addison-Wesley, 1992).