There have been some major changes from the EIA/TIA 568A to the EIA/TIA 568B and 569 standards transition. One of the major changes is that the telecommunications closet has evolved into the telecommunications room. These rooms are
to be floor-serving facilities for horizontal cable distribution, and they also can be used for intermediate and main cross connects.
The telecommunications room is now defined for design and equipment according to ANSI/TIA/EIA 569A. Some of the specifications include specifications for wire management,
stress from tight bends, cable ties,
, and so on. Horizontal cable terminations cannot be used to administer cabling system changes. Jumpers, patch cords, or equipment cords are required for reconfiguring cabling connections. There's also a further restriction that application-specific electrical
cannot be installed as part of the horizontal cabling.
Additional specifications for horizontal cabling in areas with movable furniture and partitions have been included in TIA/EIA 568B.1. Horizontal cabling methodologies are specified for open office environments by a means of multiuser telecommunications outlet assemblies (MUTO). It is preferable to use MUTOs only when the entire length of the work area cord is accessible to facilitate tracing and to prevent erroneous disconnection. Up to 22
or 71 feet of work area cable are allowed.
Consolidation points or transition point connectors are interfaces between the patch panels and MUTOs.
General Horizontal Cabling Subsystem Specifications
Note that the ISO/IEC 11801 allows 120 and
twisted-pair horizontal cabling. Grounding must conform to
building codes as well as ANSI/EIA/TIA 607. You must have a minimum of two telecommunications outlets in the work area. The first outlet must have a 100-ohm twisted-pair category 5E, and the
outlet must also have one outlet with twisted-pair Category 5E. Two-fiber multi-mode optical fiber must also be installed.
Additional outlets can be provided. These outlets are in addition to and cannot be
by the minimum requirements of the standard. Bridged taps and splices are not allowed for
-based horizontal cabling. Additional specific components cannot be installed as part of the horizontal cabling. When needed, they must be placed external to the telecommunications outlet or horizontal cross connects.
Finally, the proximity of horizontal cabling to sources of electromagnetic interference should be taken into account.
Documenting and the Administration of the Installation
When in place, the wiring plant is not a static, immobile structure. It is a dynamic and evolving part of your network. If the plant is not
with an up-to-date documented record, then any additions, changes, moves, and upgrading are out of the question.
The TIA/EIA-606 standard provides a guide to documenting a cabling system to make its administration efficient and effective. This provides the administrator with several benefits:
Allows better asset management
Increases network reliability and up time
Facilitates movement, additions, and changes
Allows for disaster recovery plans
Allows for capacity planning, upgrading, and acceptance of new emerging applications
Allows the generation of management
Documentation should include equipment and component labels, electronic or real records, drawings, work orders, and reports. Realistically, every piece of the physical plant should be labeled. This includes cables, termination hardware, cross connects, patch panels, closets, and anything else that will assist you in developing a meaningful overall view of your system.
Good labeling requires a unique coding scheme that makes sense to you. The label can include a location scheme, a component scheme, or a combination of both. You must realize that a label cannot have all the required information for a specific component, so it should contain enough information to uniquely define the component and point to a specific record. These pointers, sometimes referred to as linkages, will point to other records.
The TIA/EIA 606 standard divides a record into four types of information:
” The essential information about the component.
” Links to other records.
” Additional information that makes the record understandable and comprehensive.
” Links to additional records that might be helpful to include. For example, if you are connecting a new PC in a new work area, you might want to include a linkage from the PC record to the record for the new workstation.
Drawings are an essential part of your physical plant. They are necessary to locate components within a building. Drawings,
"as built" drawings, will show the locations of
, pull boxes, and other components hidden from view behind walls and ceilings and under floors. These enable you, your
, and network administrators to define and control space requirements, estimate cable
, and keep track of equipment. In other words, you need to document your network. In Chapter 3, "Network Design Strategies," you can learn about several applications and techniques that can be used to assist you in keeping track of your cable installations, as well as other components in your network.
Work orders should record all equipment and cabling moves, adds, and changes. This should form a history of the cabling system's life or evolution. The records of the pertinent equipment involved should be updated every time the work order is performed.
of records organized in a specific manner. This can be in the form of a database that can be selected to show a selected part of a record. For example, a report might show the number of hard
on a specific server, or it can show the cables running to the device. You can include the hard drive identifiers or, in the case of the cables, the cable
Several types of cable management software are available that can be used to maintain records and generate reports. There are also specific programs aimed at managing a cabling system. These programs are compatible with structured cabling systems and conform to the TIA/EIA standards.