Cisco Networking Academy Program CCNA 1 and 2 Companion Guide, Revised part 93 is the Cisco approved textbook to use alongside version of the Cisco Networking Academy Program CCNA 1 and CCNA 2 web-based courses. The topics covered provide you with the necessary knowledge to begin your preparation for the CCNA certification exam (640-801, or 640-821 and 640-811) and to enter the field of network administration. | Page 889 Tuesday May 20 2003 4 54 PM Structured Cabling Systems Standards and Codes 889 Servicing the Work Area Patching is done when connectivity changes are needed often or are foreseen. It is much easier to patch cable from the work area outlet to a new position in the TR than it is to remove terminated wires from connected hardware and reterminate them to another circuit. Patch cords also are used to connect networking equipment to the cross-connects in a TR. Patch cords are limited by the TIA standard to 5m ft. . A uniform wiring plan must be used throughout a patch panel system. All jacks and patch panels should be wired using the same wiring plan. If the T568A wiring plan is used for the information outlets or jacks T568A patch panels should be used. The same is true for the T568B wiring plan. Patch panels can be for unshielded twisted-pair UTP shielded twisted-pair STP or fiber-optic connections. The most common patch panels are for UTP. These patch panels use RJ-45 jacks patch cords with RJ-45 plugs connect to these ports. In most facilities there is no provision to keep authorized maintenance personnel from installing unauthorized patches or installing an unauthorized hub into a circuit. There is an emerging family of automated patch panels however which can provide extensive network monitoring in addition to simplifying the provisioning of moves adds and changes. These patch panels normally provide an indicator lamp over any patch cord that need to be removed and then once the cord is released provide a second light over the jack to which they should be re-affixed. In this way the system can automatically guide a relatively unskilled employee through moves adds and changes. The same mechanism that detects when the operator has moved a given jack works also to detect when a jack has been pulled. An unauthorized resetting of a patch can trigger an event in the system log and if need be trigger an alarm. For example if a .