Eliminating recurring problems is always a plus when depending on a network. There are underlying basics that can eliminate some of the causes of problems. In the last issue we discussed the use of power back up systems to eliminate power problems and provide your system with clean and constant power. This issue we will focus on another facet of a network that should never be a problem, but often is: cabling infrastructure.


Cabling Infrastructure

Cabling infrastructure for this discussion means the cabling “in the wall”. It is installed to form a backbone for the network. The rest of your network equipment plugs into it. A typical Ethernet system has a connection at each computer that is cabled back to a central location. This is called the MDF, or Main Distribution Frame. In larger systems there may be multiple central locations that are then wired together. These are called IDF’s (Intermediate Distribution Frames).

Over the last ten years, industry standards have been developed which have helped to define the throughput, or bandwidth, of network designs. New technologies are developed every day making the selection of the equipment and wiring somewhat of a moving target. The best cabling infrastructure designs are comprised of recent technology with flexibility to change as new products are introduced.

The selection of your cabling infrastructure comes down to speed versus cost. These days, the most practical is called 10/100BASE-T Ethernet. If you contemplate moving large files along your network, then 1000BASE-T (Gigabit Ethernet) or even fiber optics may be the proper solution. To help with defining your needs and the cost of each system, consult with a network professional and a reputable cabling contractor.


Identifying Potential Problems

Properly terminated cables retain the jacket up to the jack insert.

Many smaller offices have a talented network administrator who runs a few cables here and there. Some have had experience wiring a home phone, or relocating a phone jack. Because basic phone cabling is so straightforward and easy, when network cabling came along, many people felt qualified to install it. Networks require noise-free, high quality connections from point to point. If there is a slow spot anywhere along the connection, then the network runs at that slow speed.

There are guidelines to handling the cable itself. For instance, no more than 25 pounds of force should be used to pull the cable and it should not be allowed to kink, knot or snag while pulling it off the spool or out of the box. Deforming the pair-twist will alter the performance of the cable. There are devices designed to support and contain cables. Cables should not be hung over nails or held with twist ties.

When using cable ties, cables should not be overstressed by over tightening, especially to the point where crush-stress is visible. Where cables turn, sweeping bends are recommended; the wire should never be bent to form right angles or sharp bends.

A properly installed cable end should retain the cable jacket as close to the termination point as possible and maintain pair twists to within 1/2 inch of the termination point.

At the central location, it is important to land the cables on a sturdy rack or other platform so that the cables cannot be disturbed. Along the route, the cables should be secured so they remain in place should someone be working around them.

The components used in a cabling infrastructure do not degrade over time, therefore, once a cable is installed and secured properly, it should be trouble-free for the life of the network, unless it is disturbed.

Each cable should be certified with an appropriate analyzer to ensure that it will perform at the desired speed. Testing devices start around $4,000.00 and provide a written report showing the performance of each cable. Common parameters are attenuation, ambient noise level, NEXT, cable length and continuity, shield continuity, crossed pairs, time and test date, and cable number.

Choosing the right kind of cabling for your network application, installing it properly and verifying compliance with the necessary standards is the key to getting the most out of your network investment. Taking a casual attitude towards the design or installation of your network cabling infrastructure could cost you dearly in troubleshooting and downtime.