When developing 568B, the TR-42 Committee relegated the specifications for Category 5 cabling to Annex D.
For many installers and users of premises and campus cabling systems, work contracts frequently include boilerplate language because some responsibilities remain constant from job to job. In many cases, that boilerplate language includes references to certain documents developed by the Telecommunications Indus-try Association (TIA-www.tiaonline.org) and approved by the American National Standards Institute (ANSI-www.ansi.org). Some of these documents are formally called standards, and others are known as Telecommunications Sys-tems Bulletins, or TSBs.
For example, TIA/EIA-606 is a standard that addresses the administration of installed cabling systems. It is sometimes referred to as "the labeling standard," because it deals with proper labeling of installed links. On the other hand, specifications for open-office horizontal cabling-frequently referred to as "zone cabling"-are contained in TSB-75 "Additional Horizontal Cabling Practices for Open Offices." Or, at least, those specifications were in TSB-75, until recently. Technically, TSB-75 does not exist anymore, having been withdrawn by the TIA in late May. TSB-75 is one of several TSBs, as well as one interim standard, that TIA withdrew in the wake of some recent accomplishments by the group's TR-42 Engineering Committee.
These developments likely will affect the language that appears in many contracts today. As of March 2001, the TR-42 Engineering Committee had completed and sent to the publisher all sections of the TIA/EIA-568B standard, which is a revision of the long-standing and often-referenced 568A standard. As part of the effort to update 568A, the group incorporated the addenda to 568A, as well as several TSBs that had been published in the meantime, into 568B. In particular, the specifications from TSB-75 "Additional Horizontal Cabling Practices for Open Offices" and TSB-72 "Centralized Optical Fiber Cabling Guidelines," as well as the specifications from Addendum 5 that define Category 5e cabling systems, now reside in TIA/EIA-568B.1.
So, if you are about to enter into a cabling contract that references TSB-72, TSB-75, or Addendum 5 to TIA/EIA-568A, then technically the contract is inaccurate. This does not mean, however, that you cannot contract for a centralized optical-fiber cabling system, an open-office cabling system, or a Category 5e cabling system. What it means is that in order to comply with the "letter of the law," any reference to a TIA standard as it concerns those cabling-system types should be a reference to TIA/EIA-568B.1.
Another development that emerged while 568B was being crafted has been chronicled before but is worth another mention. When developing 568B, the TR-42 Committee relegated the specifications for Category 5 cabling to Annex D. The group now recommends Category 5e cabling as the minimum performance level. Along with the relegation of Category 5 to Annex D, the TIA withdrew two TSBs that addressed testing of Category 5 systems. Specifically, the TIA withdrew TSB-67 "Transmission Perfor-mance Specifications for Field Testing of Unshielded Twisted-Pair Cabling Sys -tems" and TSB-95 "Additional Transmission Performance Guidelines for 4-Pair 100-ohm Category 5 Cabling." So, any reference to either document is technically invalid. The bottom line here is that if your goal is to specify a TIA/EIA-568B-compliant twisted-pair cabling system, that system should achieve Category 5e performance.
On several levels, the ratification of TIA/EIA-568B should make specifying cabling projects easier. It incorporates specifications for both twisted-pair and fiber-optic premises and campus cabling systems, thereby allowing professionals to reference a single document for most projects. But like many other forms of change, it will require many in the industry to break old habits. And in this case, it will require rewriting some of the boilerplate language in contracts.
Ryan Clicheis Assistant Editor with Cabling Installation & Maintenance.