s Network Communications Council honored her as the Professor of the Year. The Essential Guide to Telecommunications has been translated into nine languages since its first edition, which was published in 1997. You can find more information at her web site, www.doddontheline.com. xxvii This page intentionally left blank Part / Enabling Technologies, Data Centers, and VolP PBXs Chapter 1 Computing and Enabling Technologies Chapter 2 Data Centers and Internet Protocol Private Branch Exchanges This page intentionally left blank Computing and Enabling Technologies In this chapter: Key Underlying Technologies Sending Data in Packets Deep Packet Inspection: Traffic Management and Monitoring Compression Increasing Network Capabilities via Multiplexing Wide Area Network Acceleration and Optimization Using Protocols to Establish a Common Set of Rules Protocols and Layers Cloud Computing Single Servers Functioning as Multiple Servers via Virtualization Network Cabling Summary Appendix Computing and Enabling Technologies T he pace of technological advancement is faster today than ever before. The pace of change in networks began increasing in the late 1980s, and further escalated in the late 1990s with the increase in the number of personal computers at enterprises and homes, growing mobile phone usage, and the growth in both total Internet and multimedia traf- fic. Unlike earlier improvements during the 1900s, these more recent changes directly impact the way people socialize and how day-to-day business is conducted. Initially, even with the proliferation of corporate personal computers in the 1980s, electronic communication among staff members was restricted to within the same building. Gradually, increasing speeds of internal networks and affordable fiber links between buildings made it feasible to link all sites within organizations. Later, the advent of powerful microprocessors and manufacturing economies of scale made computer ownership feasible for residential consumers. Affordable, high-speed Inter- net access for c