STEPHEN A. THOMAS is Chief Technical Officer and Vice President of Engineering for TransNexus, a company developing Internet telephony products. He has over a decade of experience working on TCP/IP and Internet technologies, including helping to create some of the TCP/IP standards. His last book, IPng and the TCP/IP Protocols: Implementing the Next Generation Internet (Wiley), is widely recognized as the network manager's best reference on the future of IP networking. SUE PLUMLEY is founder of Humble Opinions, a consulting group specializing in Novell and Microsoft networks. She has written an...