Cabling System Design and Installation

Understanding how to put the components together into a cohesive cabling system design is very important. Each of the components of a cabling system can fit together in many different ways.  Additionally, you must design the cabling system so that each component of that system meets or exceeds the goals of the cabling project.

Identify and understand the elements of a successful cabling installation

Before designing your system, you should understand how the following elements contribute to asuccessful installation:

1. Using proper design

2. Using quality materials

3. Practicing good workmanship

Each of these aspects can drastically affect network performance.

>> Proper Design

A proper cabling system design is paramount to a well-functioning cabling infrastructure. As with any other major project, the key to a successful cabling installation is this word: PLAN. A proper cabling system design is simply a plan for installing the cable runs and their associated devices. So what is a proper design? A proper cabling system design takes into account five primary criteria:

a. Desired standards and performance characteristics

b. Flexibility

c. Longevity

d. Ease of administration

e. Economy

Failure to think about these standards will lead to usability problems and bad network performance.

>> Quality Materials

Another element of a successful cabling installation is the use of quality materials. The quality of the materials used in a cabling installation will directly affect the transmission efficiency of a network. Many times, a vendor will sell many different cabling product lines, each with a different price point. The old adage that you get what you pay for really does apply to cabling supplies.

But that doesn't always mean that low price means low quality. Some providers make low price, high quality cabling supplies. In addition to price, you should check how the product is assembled. Qaulity materials are sturdy and well constructed. Low-quality materials will not be durable and may actually break while you are handling them.

>> Good Workmanship

There is a saying that any job worth doing is worth doing correctly. When installing cabling, this saying is especially true because shoddy workmanship can cause data transmission problems and thus lower the network's effective throughput. If you try to rush a cabling job to meet a deadline, you will usually end up doing some or the entire job over again.

Identify the pros and cons of network topologies

A topology is basically a map of a network. The physical topology of a network describes the layout of the cables and workstations and the location of all network components. Choosing the layout of how computers will be connected in a company’s network is critical. It is one of the first choices you will make during thedesign of the cabling system, and it is an important one because it tells you how the cables are to be run during the installation.

In this article "How To Choose the Correct Cabling" was described the basics of the hierarchical star, bus, and ring topologies. Here, we'll look at some of their advantages and disadvantages.

The advantages of Hierarchical Star Topology as following:

. It can be reconfigured quickly.

. A single cable failure won't bring down the entire network.

. It is relatively easy to troubleshoot.

. It allows the ability to centralize electronics and run fiber to the desk using the centralized cabling option.

. It also allows an end user to run backbone cables to telecommunications enclosures, also called FTTE.

. It is the only recognized topology in the industry standard, ANSI/TIA-568-C.

The disadvantges of Hierarchical Star Topology as following:

. The total installation cost can be higher than that of bus and ring topologies because of the larger number of cables.

. It has a single point of failure: the main hub.

The advantages of bus topology as following:

. It is simple to install.

. It is relatively inexpensive.

. It uses less cable than other topologies.

On the other hand, a bus topology has the following disadvantages:

. It is difficult to move and change.

. The topology has little fault tolerance (a single fault can bring down the entire network).

. It is difficult to troubleshoot.

Ring Topology

The ring topology has a few pros but many more cons, which is why it is seldom used. On thepro side, the ring topology is relatively easy to troubleshoot.

The cons are as follows:

. It is expensive because multiple cables are needed for each workstation.

. It is difficult to reconfigure.

. It is not fault tolerant. A single cable fault can bring down the entire network.

Selecting the Right Topology

From a practical standpoint, which topology to use has been decided for you. Because of its clear-cut advantages, the hierarchical star topology is the only recognized physical layout in ANSI/TIA-568-C. Unless you insist that your installation defy the standard, this will be the topology selected by your cabling system designer.

Understand cable installation procedures

A cabling installation involves five steps:

1. Design the cabling system.

2. Schedule the installation.

3. Install the cables.

4. Terminate the cables.

5. Test the installation.

>> Design the Cabling System

Following proper cabling design procedures will ensure the success of your cabling system installation is very important. Before you pull a single cable, you should have a detailed plan of how the installation will proceed. You should also know the scope of the project. Finally, you should have the design plan available to all people involved with the installation of the cable. Be sure to include anyone who needs to refer to the way the cabling is being installed. At the very least, this information should contain a blueprint of how the cables will be installed.

>> Schedule the Installation

In addition to having a proper cabling design, you should know approximately how long the installation will take and pick the best time to do it. From a planning standpoint, this is approximately the same time in new construction when the electrical cabling is installed.

For a post construction installation, you should schedule it so as to have the least impact on the building’s occupants and on the existing network or existing building infrastructure. It also works to schedule it in phases or sections.

>> Install the Cabling

Once you have a design and a proper schedule, you can proceed with the installation. We'll start with a discussion of the tools you will need.

The cabling tools as following:

. Pen and paper

. Hand tools

. Cable spool racks

. Fish tape

. Pull string

. Cable-pulling lubricant

. Two-way radio

. Labeling materials

. Tennis ball

Cabling system Documentation

Cabling system documentation includes information about what components make up a cabling system, how it is put together, and where to find individual cables. This information is compiled in a set of documents that can be referred to by the network administrator or cabling installer any time moves, additions, or changes need to be made to the cabling system.

The most useful piece of cabling system documentation is the cabling map. Just as its name implies, a cabling map indicates where every cable starts and ends. It also indicates approximately where each cable runs. Additionally, a cabling map can indicate the location of workstations, segments, hubs, routers, closets, and other cabling devices.

>> Terminate the Cable

Terminating the cables involves installing some kind of connector on each end (either a connector or a termination block) so that the cabling system can be accessed by the devices that are going to use it. This is the part of cabling system installation that requires the most painstaking attention to detail, because the quality of the termination greatly affects the quality of the signal being transmitted. Sloppy termination will yield an installation that won’t support higher- speed technologies.

Though many termination methods are used, they can be classified one of two ways: connectorizing or patch panel termination. Patch Panels have many different types, some for copper, some for fiber. Copper cable patch panels for UTP all have a few similar characteristics, for the most part. During termination, the individual conductors in the UTP Cable are pressed between the metal blades to make both the mechanical and electrical connection between the cable and the connector on the front of the patch panel. This type of patch panel is a 110-punch-down block (or 110-block, for short).

Figure 1 shows a sample patch panel

>> Test the Installation

Once you have a cable or cables installed and terminated, your last installation step is to test the connection. Each connection must be tested for proper operation, category rating, and possible connection problems. If the connection has problems, it must either be re-terminated or, in the worst-case scenario, the entire cable must be re-pulled.

Testing individual cables is done most effectively and quickly with a LAN Cable Tester (as shown in Figure 2. Cable testers are available for both copper and fiber optic cables.

Figure 2 shows Network LAN Cable Tester CT-168

You should test the entire cabling installation before installing any other hardware (hubs,PCs, etc.). That way, you avoid having to troubleshoot cabling-related problems later (or at least you minimize possible later problems).