Wednesday, December 5, 2012

Structured Network Cabling Primer (Part 1 of 3)

Structured Network Cabling Primer

Part 1 of 3

As more and more services (e.g., Google Apps) move to cloud computing models, the more important having a fast, reliable network is to your organization. Therefore, its important to have a general understanding to better interact with network engineers and technicians who support your network. This article provides a high-level overview of the typical components of a Structured Network Cabling system.

Structured Network Cabling techniques are employed to design and build networks in as close to a "standard" way as possible.  By using predictable wiring and cabling techniques, the process of troubleshooting problems and adopting to the inevitable Moves, Adds, and Changes becomes simpler, faster, and, ultimately, more cost-effective.

That is, designing a network using Structured Cabling techniques can save you money! These savings are over and above the cost-saving effects of using Google services and other cloud computing solutions.

So, let's start with the components of a structured network that are the closest to your users and move outward from there.

Environments and components of a typical network
Environments and components of a typical network

The Office

A typical office tends to have devices that obviously go on the network, such as desktops, laptops, networked printers, etc.  However, more and more devices that generally aren't thought of in a network or office situation are finding themselves on the network now, such as televisions, projectors, gaming consoles, and more. Some of these are used with cloud-related applications.

Networked devices tend to have a port on the back that allows the user to connect the device to the network.  This modular port or jack or socket is typically labeled as an "Ethernet Port" or "Network Jack" or some variation on that theme.  This port is usually of the 8 position, 8 conductor variety (e.g. 8P8C) that is designed to accept a RJ45 plug.  An 8P8C RJ45 plug looks like a bigger version of a phone plug.

For future reference, ports, jacks, sockets, and outlets are of the "female" gender while plugs are of the "male" gender.  That is, you insert a plug into a port.

Ports vs. Plugs
Ports vs. Plugs
After considering the device and the device's network port, the next item typically encountered is the cable to be plugged into the network port.  This cable is called a Patch Cable or a Patch Cord.  It's flexible, fairly short (generally less than 15 feet, usually closer to 6 feet), and has plugs on both ends.  These cables are usually "Unshielded Twisted Pair" cables, or UTP.  Each cable contains 4 pairs of copper conductors (wires); each pair is twisted between 2 - 24 times per foot of cable.  This twisting of conductors helps neutralize the interference that one conductor may cause in another conductor.

There are a variety of different types of UTP cables, each designed to perform to a certain specification.  Common types include "Category 3" (typically for voice-grade communications as well as older, slower data-grade communications), "Category 5," "Category 5e" (typically for high-speed data communications), and "Category 6" (the most recent standard, used with very high-speed data communications).  The word "category" is often abbreviated to "cat" resulting in, for example, "Cat5e cable."

Patch cables are plugged into the network device (e.g., a computer) on one end and into an outlet (or jack, port, etc.) in a wallplate on the other end.  Wallplates can be affixed to a box that's either embedded in the wall (or floor), or is mounted onto the surface of the wall with a metal or plastic tube (called "raceway" or "conduit") that protects cabling from the office environment.

These wallplates and their outlets are generalized to as a "Work Area Outlet" (or "WAO" for short).
A work outlet
A work outlet
This encapsulates most of what the typical user sees of the network -- their devices, the outlets in the wall (WAOs), and the patch cables that connect the two together.  The next step (part 2) will be to explore the wiring closets and their relationship to office environments.

-- Wes Dean, a Google Apps Certified Deployment Specialist and a Google Apps Trusted Tester, is Principal of KDA Web Technologies, a Google Apps Authorized Reseller. To learn how Wes and KDA Web Technologies can help you, go to