It’s easier when you speak the language

Only a couple of years ago, corporate networks were the wave of the future. Networks were often referred to as “strategic investments” by the “C-men”—CEOs, CFOs and the rapidly disappearing CIO (chief information officer). They supported corporate Web sites, e-business, MRP, ERP, CRM and an alphabet soup of applications that consultants had convinced these executives wee the new world of business.

Not any more. Millions of dollars wasted on vague ideas are a thing of the past. Executives have other things on their minds, like keeping the business liquid and perhaps staying out of jail. Networks are no longer tactical purchases but an inseparable part of the corporate structure, supporting communications among employees and with the outside world.

However, responsibility for keeping the network going has reverted to the information technology (IT) or network manager. These folks have got a lot more on their minds than cabling. They have to worry about the network equipment attached to the cabling, the PCs attached to the network equipment, software running on the PCs, backup power and keeping all users satisfied. They have to worry about training users and answering their technical questions. They have to deal with software upgrades, viruses and hackers.

Cabling is a minor concern to an IT manager, representing only a small percentage of the budget, and gets attention only when the network needs more user drops; moves, adds and changes (MACs); or repair of damaged cables.

Working with IT managers

First learn to speak their language. Know a bit about the network, the latest technology and the best investments. Be technically savvy about cabling. Quote complete jobs and do the job right the first time.

Cabling people talk Category 5e, Category 6, laser-rated fiber and SFF connectors. IT people talk Ethernet, operating systems, applications software, and hubs and switches, which are the heart of the network and are connected by the cabling.

While it’s unlikely you’ll deal with software issues, you should know that Ethernet is the network that all the cabling supports. Ethernet defines the network’s “language”—how devices and computers talk to each other. It includes how data is formatted into packets or files of data signals and the address structure for all the connected devices. Ethernet is what runs the network.

The network (Figure 1) consists of a computer room filled with servers—big computers that store and process data for all the users—whose PCs are called clients. The servers connect to the corporate network through large hubs or switches that are tied to smaller local hubs or switches in telecom closets through the backbone cabling. That backbone cabling is probably fiber optics. The local hubs or switches are connected to individual users over shorter links, called horizontal cabling, which is typically Category 5e or Category 6.

These servers connect to the outside world using specialized hubs called routers. These routers are like hubs, but are able to talk to and communicate over the Internet or a public switched phone system.

Hubs (Figure 2) are simple repeaters that allow multiple PCs or other hubs and switches to talk to each other. A signal coming into any hub port is repeated to all output ports so the signal is broadcast to all other users, allowing any connected equipment to talk to all others. But whenever a hub accepts an input signal, it ties up all the ports while the signal may be directed to only one of them. This reduces network efficiency.

A switch (Figure 3) looks like a hub, but has more internal-processing capability. It analyzes every incoming signal, reading the address to which it is directed. The switch then sends that signal to the appropriate port only, leaving other ports available for handling other signals. As you can see from Figures 1 and 2, the hub can only support one signal, while the switch can support signals equal to as many as half the number of ports. In our eight-port example, the switch has four times the throughput.

Don’t forget that, in addition to the computer network we are describing, there is also a telephone network running over copper wiring. It may be old, installed many years ago, or it may be using new Category 5/5e cabling installed with the last network cabling update. The phone cabling will be parallel to the computer network since it also connects to a phone on every user’s desk. At the other end you will find a phone switch, even some old PBXs (private branch exchange) and in the middle, cross connects on 66-type punchdown blocks in the telecom closets.

Where does cabling come in?

IT managers will understand hubs and routers and the rest of their network hardware and software. But they may not have cabling on their minds. They may not be worrying about power quality or data-grade grounding. Here’s where the electrical contractor who also does cabling has a big advantage over other contractors who only do VDV cabling.

Remember that cabling represents only a tiny part of the IT manager’s budget. All that hardware and software they oversee costs a lot more than the cabling. But surveys show cabling is a big problem, especially getting it installed correctly and on time. Usually price is secondary—they just need it right now.

Let me say that again—it is very important—getting cabling installed properly and on time is more important than the cost. That’s why a Category 5e “drop,” the term used for a connection between a telecom closet and the desktop, is often quoted at a fixed price, about $125-175 depending on the locality. And that is why IT managers continue doing business with people they can trust to do good work and meet deadlines; cost is not an unknown.

But what do you say when they ask what cabling system to install? Do they choose Category 5e, Category 6 or fiber optics? And if it’s fiber, do they choose the current norm of 62.5/125 or go for laser-rated 50/125? And is copper really cheaper than fiber?

Here is where your homework on cabling pays off. You need to know that all current network types up to Gigabit Ethernet work on Category 5e and that Category 6 gives more “headroom” but at a significantly higher cost and questionable interoperability. New lower-cost versions of Gigabit Ethernet may run only on Category 6. You need to be able to sketch out a centralized fiber optic cabling system that could be cheaper than copper if you factor in the power and grounds in the telecom closets.

If the IT manager is using fiber in the backbone, you must be familiar with the new laser-rated 50/125 fiber—a necessity if they expect an upgrade to 10 Gigabit Ethernet and the various types of connectors now available beyond the old faithful STs and SCs. You must point out this new fiber is incompatible with the 62.5/125 fiber they probably have already installed and requires careful management of patch cords and interconnects.

A final word about power

IT networks are expected to have high reliability—99.99 percent or more uptime. That means they require uninterruptible power in the computer room and telecom closets, and perhaps backup generators for long-term outages. Being conversant in both cabling and power gives a competitive advantage in working with the IT manager, who then has one contact point.

That is good, because he is probably up to his eyeballs in other problems, such as viruses and hackers, clueless users and bosses pushing him to cut costs. EC

HAYES is a VDV writer and trainer and the president of The Fiber Optic Association. Find him at www.JimHayes.com.