 33/6 33.6 System performance 33/6 33.7 Testing 33/7 33.8 Voice distribution frames 33/8 33.9 Computer aided cable layout 33/9 33.10 References 33/10 33.11 Appendix 33/10 This page intentionally left blank Introduction 33/3 33.1 Introduction Table 33.1 illustrates the type of cable required for various com- puter systems. Rewiring a house or even fitting an extra power socket requires a In the past the power and influence of the major computer com- large amount of effort. Multiply that by the range of voice and data panies and the absence of any alternative allowed them to force services, and the number of outlets required in a modern office users to install the cable they specified. This restricted the users' building, and the scale of the problem increases exponentially. choice when changing their computer system. Add to that the fact that the modern office is likely to have a new However, the extent and variety of communications in the modern tenant every few years and the needs of these tenants will change. office and the introduction of standards has changed the emphasis. Also the wiring records are likely to be either out of date or lost. Today the user can install cables which meet internationally The answer to this chaos is a structured cabling system! In the recognised standards and the equipment manufacturers can design following paragraphs some of the considerations of office cabling equipment to conform with the same standard. All manufacturers systems and their data networks are described. This is followed by equipment will run over the medias defined in the standard. It is the a definition of a structured cabling system and the way in which advent of standards like EIA/TIA 568, IEEE 802.3i 10BaseT and the various networks are implemented in structured cabling systems. more general acceptance of twisted pair cables that has made this The chapter concludes with a description of computer aided cable approach possible. layout techniques. A vendor independent cabling system uses cables of internation- al