Technical Bulletin

The TIA/EIA-568-A Category 5 UTP (and Beyond) Patch-Cord Management,
Bend-Radius Stability, and Performance as it Applies to the PerfectPatch.

An industry study* recently conducted by PerfectSite Corporation, an international structured-cabling consulting firm, has revealed data that shows 93% of all installed modular patch cords exhibit slack, the #1 problem in patch-cord management. This results in the system being unmanageable, negatively affecting bend-radius stability and patch-field aesthetics. This can directly affect the speed with which faults can be identified and rectified.

In order to combat this problem, the PerfectPatch was developed as a unique (patent pending/multiple filings) design component for reducing patch-cord slack while maintaining TIA/EIA-568-A/TSB67, Category 5, channel and beyond performance requirements. PerfectSite developed a testing methodology and performed extensive tests on the PerfectPatch^TM in its own lab. The testing procedures and results were validated by an independent testing laboratory, ETL Laboratories.

After 21,200+ applications of the PerfectPatch, all cables and patch cords passed Category 5 and beyond performance requirements. The PerfectPatch provided non-load-bearing and bend-radius stability in high performance patch cords and increased patch-cord management performance.

Upon developing a structured-cabling-system strategy, one must take into consideration the System Functional Performance Level ("Standards Update: Year of Aesthetics," BICSI NEWS, January 1997), which can be broken down into three interdependent components (see figure 1).

• Component performance level - addressed by TIA/EIA-568-A. The first line of defense. If a component doesn't pass specifications, the faulty component(s) must be replaced.
  
  
• Installation performance level - addressed by TIA/EIA-568-A and others. Components are manufactured, based on certain installation requirements, and can be tested out in the field, as specified, in accordance with TSB67 for UTP cabling systems, Section 12 of the 568-A for attenuation losses in fiber cabling systems or other measurable means based on cable and passive components in a structured cabling system.
  
  
• Management performance level - addressed by the Industry. The impact of management on the speed with which faults can be identified and rectified.
  

A category level of component performance has been determined in TIA/EIA-568-A, such as Categories 3, 4, and 5. Basic link and channel performance requirements have been established in TSB67 for the installation of the components in a system. The management performance level, briefly addressed in the standards, is more subjective than the aforementioned, but is equally important to the speed at which faults can be identified and rectified.

A typical horizontal cross-connect (HC), where a high concentration of patch cords are being utilized in a network environment, is constantly in a state of flux with moves, additions, and changes, which can all affect bend-radius stability in patch cords. Problems in electrical performance, manifesting in signal degradation from kinked cables or loose connections, are exacerbated by excess stress put on the cables from patch-cord slack and the "entangling effect" of nested patch cords.

Bend-radius stability is the patch-cord radius' resistance to change in its environment (typically dynamic at HCs). With a stable radius, patch cords provide the integrity necessary to ensure a static environment needed for TIA/EIA-568-A/TSB67 channel performance. Bend-radius stability eliminates the possibility of damage that can occur in an uncontrolled patch-cord management system from stress on the connectors and kinking.

Bend-radius stability can be compared to running water in a garden hose. When you "kink" the hose, little, if any, water will come out (see figure 2). Let's say you were to wrap that hose around a small pipe (KinkGuard^TM) of optimal diameter and secure the hose to reduce the load (pulling) on the hose. You would not lose water pressure despite the bend in the hose (see figure 3).

This is the concept that the PerfectPatch utilizes to protect the patch cord and provide maximum transmission performance. In a patch-cord management system (typically a "rat's nest") there is no way to ensure bend-radius stability and, thus, the protection and performance of the patch cord. One must realize that Category 5 channel performance is at its best when the cabling system is in a stable environment. The more alterations to your patch cords or system, the more it can affect your data transmission (just as the kink in the hose affected the water pressure).

The purpose of the testing, performed at an independent testing facility (ETL Laboratories), was to validate the initial test results of the PerfectPatch. Specifically, these tests applied to Category 5, 100 ohm, balanced UTP, solid and stranded patch cables and assembled cords. The tests were to determine if it would meet the Category 5, TIA/EIA-568-A/TSB67 channel performance requirements as stated in the standard. Tests were performed on HP network analyzers as well as Category 5 (level 2) hand-held field testers.

PerfectSite performed over 200 applications (see figure 4, Cable Test) of the PerfectPatch to a selected 7-foot segment of 100 meters (328 ft.) of cable. This procedure was replicated for each of 6 different manufacturers (1200 total applications) who produce stranded and solid UTP Category 5 patch cable. The transmission requirements (section 10.2.4 - 10.2.4.9 with the exception of 10.2.4.6 "attenuation" which was substituted with 10.5.4.1 for stranded cable only as required) were used as stated for UTP in the TIA/EIA-568-A.

The results revealed negligible change in the cable electrical performance (see figure 5, stranded patch cable), when utilizing a HP network analyzer in the NEXT and Attenuation. These are more stringent parameter tests than are required by TSB67 channel tests. All of the cables tested (stranded and solid) passed these and other requirements.

All Cables Passed with the PerfectPatch.

A 7-foot segment, where the 200 applications of the PerfectPatch were applied, was removed from the 100-meter length (see Figure 4, Channel Test). Eight-position, modular plugs were installed on each end of this segment, and channel testing with field testers was performed as indicated in TIA/EIA-568-A/TSB67. All of the patch cords tested passed this and additional specifications.

Although extensive testing on patch cables was performed on network analyzers with ETL verified results, 20,000 applications of the PerfectPatch were also tested (see figure 6).

These applications were tested with four different leading manufacturers of Category 5 (Level 2) hand-held testers and 100 each, Category 5, TIA/EIA-568-A/TSB67 channel-qualified patch cords. All 20,000 applications of the PerfectPatch passed TIA/EIA-568-A/TSB67 channel requirements (see figure 7).

Because the PerfectPatch deals with the completed channel, the end user and installers have the ability to check the product themselves, out in the field - where it counts.

Cabling Practices, Telecommunication Closets, section 7.4, and Equipment Rooms, section 8.4, state: "Appropriate cable routing and dressing fixtures should be used for effective organization and management of the different types of cables in telecommunications closets."

In real life, this is not being achieved. A recent industry study on patch-cord management confirms this. Patch-cord management's #1 problem, slack in patch cords, plus the poor management and unmanageability that accompany slack, has not been effectively dealt with by our Industry until now. This "rat's nest" situation is in clear violation of the spirit of the TIA/EIA-568-A standard.

Patch-cord bend radius is one of the industry's biggest misconceptions. The bend radius is covered in section 10.6.3.2, Cabling Practices for UTP Horizontal Cable, "Also, in spaces with UTP terminations, cable-bend radii shall not be less than four times the cable diameter for horizontal cable." This applies to termination on the back of the patch panel (see Figure 8) where the horizontal cables terminate. There is no requirement for patch-cord bend radius because there had been no testing performed on non-load-bearing bend radius for patch cords prior to the PerfectPatch. Also, there was no way to stabilize the radius on patch cords until now.

While the standards do not address the bend radius of patch cords, neither do they advocate the kinking of patch cords, which can lead to signal degradation in copper and broken glass in fiber patch cords.

Isolating the cable itself and using HP Network analyzers and the test requirements for cable in the TIA/EIA-568-A allowed us to examine the effects of the PerfectPatch on the cable itself. This is a more stringent requirement than required by TSB67 channel performance requirements. All tests on the cable and the additional tests performed on Level 2 hand-held field testers have proved that the PerfectPatchwith its non-load-bearing KinkGuard^TM performs well beyond all Category 5, TIA/EIA-568-A/TSB67 channel requirements (see Technical Bulletin - Performance for Fiber Optics).

PerfectPatch Part Number PP-350

PerfectPatch PP-350 is the only product in the market that can reduce patch-cord slack, the #1 problem with patch-cord management. It is also the only product to provide bend-radius stability with a non-load-bearing radius (KinkGuardTM) at Category 5, channel performance levels and beyond. This product is proven to increase patch-cord performance, management and aesthetics.