How a patch cord is routed - the key to designing a management system.
When designing a patch-cord management system, what often happens is the overlooking of an obvious point . The simple task of determining how patch cords will be installed prior to the implementation of the management system must be analized so that a designer can implement the right management for the job.

How patch cord should be routed.
The object of routing a patch cord through horizontal and vertical managers is to route the cord in such a fashion that will eliminate or minimize the #1 contributor to poor patch-cord management, SLACK. Since you cannot purchase the exact length cord for each patch, you must purchase longer cords to give you the flexibility needed for moves, adds, or changes.

Although routing a patch cord to eliminate or minimize slack seems like a simple concept, it does not work. For this method to work and to minimize the slack of the cord it would require the end user to possibly figure out a new route each time a cord is patched. It's like reading a map. You would have to look at the wire manager's routes, and the patch- cord length, see that if you were to route it through this horizontal manager, then take it down these vertical managers, to see that you would end up with very little slack when the patch is completed, or to see if another route would be better. See what I mean!

How a patch cord is really routed.
Even with horizontal and vertical managers on each side of a patch panel or hub, the patch cord follows the path of least resistance, just like electricity. The cord enters the horizontal manager adjacent to the patch panel, whips over to the immediate vertical manager, and travels down the verticals to the horizontal manager adjacent to the hub. Boom, the patch is complete! (See fig. 1.) This leaves a preponderance of slack in one section of the management system (an Achilles' heel). This slack builds and builds as each cord is patched. (See fig. 2.) This will cause an overflow condition in the mangement system resulting in poor patch-cord management. You all know what I mean - a rat's nest, jungle, cluster****, or spaghetti.

Designing with the Achilles' Heel in mind.
As a designer of the management system you can see that the example I gave you, although it may vary with different management layouts, will produce the same results. The slack of the cords will have to be managed in only one part of the management system after the patch is complete (when patch-cord adjusters are not installed). This is where your concentrated efforts will be: eliminating or minimizing the slack at your management system Achilles' heel.
In an industry study "The reality of patch-cord management" published in Cabling Installation and Maintenance magazine (Feb. 97) the finding revealed that 93% of all patch cords exhibit unacceptable slack. More astonishing was the average amount of slack per patch cord: a whopping 20 inches. Multiplied by 187 (the average number of patch cords per Cross-connect under study), that comes to 312 feet - longer than a football field. This accumulated slack hangs in disarray, affecting channel performance, manageability, aesthetics, and bend radius stability.

Management News

Dennis W. Mazaris, RCDD, Editor

43766 Trade Center Place, Suite 130
Dulles, Virginia 20166

Next Issue
Why two 48-port patch panels instead on one 96-port panel will not remedy patch-cord management problems.