Handbook of Local Area Networks, 1998 Edition:LAN Basics Click Here! Search the site:   ITLibrary ITKnowledge EXPERT SEARCH Programming Languages Databases Security Web Services Network Services Middleware Components Operating Systems User Interfaces Groupware & Collaboration Content Management Productivity Applications Hardware Fun & Games EarthWeb sites Crossnodes Datamation Developer.com DICE EarthWeb.com EarthWeb Direct ERP Hub Gamelan GoCertify.com HTMLGoodies Intranet Journal IT Knowledge IT Library JavaGoodies JARS JavaScripts.com open source IT RoadCoders Y2K Info Previous Table of Contents Next CABLE MANAGEMENT Cable can easily become a network manager’s nightmare if it is not accurately tracked and documented. The first step in controlling and managing a wiring system is to use a standard labeling scheme during installation. The labeling scheme should make it easy to track all the components of the cabling system (e.g., wall plates, equipment rooms, termination points, cable type). Cable Labeling A standard labeling scheme in and of itself is not sufficient to manage a cable system. After the entire wiring system is designed and in place, the operational success of the wiring system depends on how well it is managed. To manage the wiring system the proper policies, procedures, and tools must be in place. Policies and procedures must dictate who has access to the wiring system and who is responsible for making modifications and handling repairs to its structure. A comprehensive set of organizational standards should be in place that covers the type of wiring to be used and where, type of wall plates, connection schemes and polarization, and cable labeling. The EIA specification suggests a cable labeling scheme based on building floor, work area, telecommunication closet used, patch panel location, punchdown block and position number. Different types of cable runs (horizontal, vertical, or station) have different associated label colors. Cable Management Software The most important tool for managing the wiring system and imposing standards is a software cable management system (CMS). Essentially this is just a data base containing details of all cable runs in the organization. The exact tool could be as simple to use as a spreadsheet. More sophisticated tools use relational data bases. Some interface with CAD packages to help in cable design. The type of tool needed depends on the size and nature of the LAN installation. Some of the major vendors of these types of packages are ISICAD Inc. (Anaheim CA), CHI/COR Information Management, Inc. (Chicago), MOD-TAP (Harvard MA), Stonehouse & Co. (Dallas TX), and the Angeles Group. When a move, add, or change is performed, the cable management software tool is used to show the current configuration and to document any change made to the wiring connections. Sometimes the same CMS is used to keep an inventory of the types and locations of end devices. Diagnostic Equipment To handle cable faults, certain diagnostic tools are needed. The CMS again may be the primary tool and will help in isolating the fault by identifying which wiring pairs are used by the end devices experiencing the problem. At some point it may become necessary to examine the wiring pairs and trace the fault to a specific cable break, miswired spot, or transmission problem. The tools needed to do this range from simple continuity testers to more sophisticated time domain reflectometers (TDRs). Continuity testers give a go or no-go answer about a wiring pair or cable connection. TDRs do the same, but can also pinpoint the location of a cable break. Optical TDRs are available for diagnosing and testing fiber media. A major vendor of cable testing equipment is Microtest Inc. (Phoenix AZ). Other tools are available to check on proper wire sequencing and to probe deeper into the characteristics of the cable (e.g., to determine noise levels and prove out transmission speeds). As the sophistication of the wire probing goes up, so does the cost of the devices. At the very least an organization has to implement some type of cable management system and have available the tools for simple go or no-go testing for each type of media used in the wiring system. SUMMARY The wiring system should not be noticed by anyone except those who manage it. The end users should see a jack on a wall plate and only understand that when their device is plugged in they have reliable LAN connectivity. To provide this transparency, the wiring system must be well planned, designed, structured, and managed. Compliance with standards, choosing media that provide room for bandwidth expansion, and using the right tools to run the system are all essential in order to make this happen. Once in place, the wiring system should provide the organization with an infrastructure for many years to come. Previous Table of Contents Next Use of this site is subject certain Terms & Conditions. Copyright (c) 1996-1999 EarthWeb, Inc.. All rights reserved. Reproduction in whole or in part in any form or medium without express written permission of EarthWeb is prohibited. Please read our privacy policy for details.