A guide to wide-area data network performance engineering. It discusses the skills needed to design a router network carrying a variety of traffic, including Internet and intranet, over frame relay devices. It covers routers, protocols including TCP/IP, SNA and Novell, protocol behaviour over a WAN, applications, performance engineering, network management and maintenance, and more. The text offers itself as a resource to keep on hand while operating, maintaining, upgrading, or migrating existing networks. It helps the reader to make difficult decisions involving hardware, software, frame relay and private lines, ATM, and application benchmarking to test new applications on the WAN.