This chapter is a survey of telecom and networking technologies that are applicable to enterprise environments. The author published one of the very first books on the topic in the early 1990s entitled Enterprise Networking: Fractional T1 to SONET, Frame Relay to BISDN (Artech House, 1993). This chapter updates that perspective for the contemporary reader, at least for a handful of telecommunications domains. After a brief overview we provide a bottom-line section in which readers interested in general trends for technology architecture planning in reference to enterprise networks, specifically for local area networks (LANs) and storage area networks (SANs), can find guidance. This is followed by sections that provide more in-depth technical details; readers just interested in the bottom line may chose to skip this material or skim through it. Chapter 10 looks at wide area network (WAN) trends.