Why Pick Copper Cabling?

Copper cabling has been around and in use since electricity was invented. And the quality of copper wire has continued to improve. Over the past 100 years, copper manufacturers have developed the refining and drawing processes so that copper is even more high quality than when it was first used for communication cabling.

High-speed technologies (such as 155Mbps ATM and 10 Gigabit Ethernet) that experts said would never run over copper wire are running over copper wiring today.

Network managers pick copper cabling for a variety of reasons: Copper cable (especially UTP cable) is as inexpensive as optical fiber and easy to install, the installation methods are well understood, and the components (patch panels, wall-plate outlets, connecting blocks, etc.) are inexpensive. Further, UTP-based equipment (PBX systems, Ethernet routers, etc.) that uses the copper cabling is much more affordable than comparable fiber equipment.

Note

The main downsides to using copper cable are that copper cable can be susceptible to outside interference (EMI), copper cable provides less bandwidth than optical fiber, and the data on copper wire is not as secure as data traveling through an optical fiber. This is not an issue for the typical installation.

Table 1 lists some of the common technologies that currently use unshielded twisted-pair Ethernet. With the advances in networking technology and twisted-pair cable, it makes you wonder what applications you will see on UTP cables in the future.

Table 1: Applications That Use Unshielded Twisted-Pair Cables 

Application	Data Rate	Encoding Scheme[*]	Pairs Required
10Base-T Ethernet	10Mbps	Manchester	2
100Base-TX Ethernet	100Mbps	4B5B/NRZI/MLT-3	2
100Base-T4 Ethernet	100Mbps	8B6T	4
1000Base-T Gigabit Ethernet	1000Mbps	PAM5	4
10GBase-T Gigabit Ethernet	10,000Mbps	PAM16/DSQ128	4
100Base-VG AnyLAN	100Mbps	5B6B/NRZ	4
4Mbps Token Ring	4Mbps	Manchester	2
16Mbps Token Ring	16Mbps	Manchester	2
ATM-25	25Mbps	NRZ	2
ATM-155	155Mbps	NRZ	2
TP-PMD (FDDI over copper)	100Mbps	MLT-3	2
[*]Encoding is a technology that allows more than one bit to be passed through a wire during a single cycle (hertz).

Picking the Right Patch Cables

Although not really part of a discussion on picking cable types for horizontal cable, the subject of patch cords should be addressed. Patch cables (or patch cords) are the cables that are used to connect 110-type connecting blocks, patch-panel ports, or telecommunication outlets (wall-plate outlets) to network equipment or telephones.

We've mentioned this before but it deserves repeating: you should purchase factory-made patch cables. Patch cables are a critical part of the link between a network device (such as a PC) and the network equipment (such as a hub). Determining appropriate transmission requirements and testing methodology for patch cords was one of the holdups in completing the ANSI/TIA/EIA-B.2-1 Category 6 specification. Low-quality, poorly made, and damaged patch cables very frequently contribute to network problems. Often the patch cable is considered the weakest link in the structured cabling system. Poorly made patch cables will contribute to attenuation loss and increased crosstalk.

Factory-made patch cables are constructed using exacting and controlled circumstances to assure reliable and consistent transmission-performance parameters. These patch cables are tested and guaranteed to perform correctly.

Patch cables are made of stranded-conductor cable to give them additional flexibility. However, stranded cable has up to 20 percent higher attenuation values than solid-conductor cable, so lengths should be kept to a minimum. The ANSI/TIA-568-C standard allows for a 5-meter (16′) maximum-length patch cable in the wiring closet and a 5-meter (16′) maximum-length patch cable at the workstation area.

Here are some suggestions to consider when purchasing patch cables:

• Don't make them yourself. Many problems result from bad patch cables.
• Choose the correct category for the performance level you want to achieve.
• Make sure the patch cables you purchase use stranded conductors for increased flexibility.
• Purchase a variety of lengths and make sure you have a few extra of each length.
• Consider purchasing patch cords from the same manufacturer that makes the cable and connecting hardware, or from manufacturers who have teamed up to provide compatible cable, patch cords, and connecting hardware. Many manufacturers are a part of such alliances.
• Consider color-coding your patch cords in the telecommunication closet. Here's an example:
  • Blue cords for workstations
  • Gray cords for voice
  • Red cords for servers
  • Green cords for hub-to-hub connections
  • Yellow for other types of connections

Types of Copper Cabling

Pick up any larger cabling catalog, and you will find myriad types of copper cables. However, many of these cables are unsuitable for data and voice communications. Often, cable is manufactured with specific purposes in mind, such as audio, doorbell, remote equipment control, or other low-speed, low-voltage applications. Cable used for data communications must support high-bandwidth applications over a wide frequency range. Even for digital telephones, the cable must be chosen correctly.

Many types of cable are used for data and telecommunications. The application you are using must be taken into consideration when choosing the type of cable you will install.Table 1 lists some of the historic and current copper cables and common applications run on them. With the UTP cabling types found in Table 1, applications that run on lower-grade cable will also run on higher grades of cable (for example, digital telephones can be used with Category 3, 4, 5, 5e, 6, or 6A cabling). Category 1, 2, 4, and 5 are no longer recognized by ANSI/TIA-568-C and should be avoided, but they are described below for historical purposes.

Table 1: Common Types of Copper Cabling and the Applications That Run on Them 

Cable Type	Common Applications
UTP Category 1 (not supported by ANSI/TIA-568-C)	Signaling, doorbells, alarm systems
UTP Category 2 (not supported by ANSI/TIA-568-C)	Digital phone systems, Apple LocalTalk
UTP Category 3	10Base-T, 4Mbps Token Ring
UTP Category 4 (not supported by ANSI/TIA-568-C)	16Mbps Token Ring
UTP Category 5 (not supported by ANSI/TIA-568-C)	100Base-TX, 1000Base-T
UTP Category 5e	100Base-TX, 1000Base-T
UTP Category 6	100Base-TX, 1000Base-T
UTP Category 6A	100Base-TX, 1000Base-T, 10 Gigabit Ethernet
Multi-pair UTP Category 3 cable	Analog and digital voice applications; 10Base-T
25 pair UTP Category 5e cable	10Base-T, 100Base-T, 1000Base-T
Shielded twisted-pair (STP or U/FTP)	4Mbps and 16Mbps Token Ring
Screened twisted-pair (ScTP or F/UTP)	100Base-TX, 1000Base-T, 10 Gigabit Ethernet
Coaxial RG-8	Thick Ethernet (10Base-5), video
Coaxial RG-58	Thin Ethernet (10Base-2)
Coaxial RG-59	CATV (community antenna television, or cable TV)
Coaxial RG-6/U	CATV, CCTV (Closed Circuit TV), satellite, HDTV, cable modem
Coaxial RG-6/U Quad Shield	Same as RG-6 with extra shielding
Coaxial RG-62	ARCnet, video, IBM 3270

Tools That a Smart Data Cable Technician Carries

Up to this point, all the tools we've described are specific to the wire-and-cable installation industry. But you'll also need everyday tools in the course of the average install. Even if you don't carry all of these (you'd clank like a knight in armor and your tool belt would hang around your knees if you did), you should at least have them handy in your arsenal of tools:

• A flat blade screwdriver and number 1 and number 2 Phillips screwdrivers. Power screwdrivers are great time-and-effort savers, but you'll still occasionally need the hand types.
• A hammer.
• Nut drivers.
• Wrenches.
• A flashlight (a no-hands or headband model is especially handy).
• A drill and bits up to 1.5″.
• A saw that can be used to cut rectangular holes in drywall for electrical boxes.
• A good pocket knife, electrician's knife, or utility knife.
• Electrician's scissors.
• A tape measure.
• Face masks to keep your lungs from getting filled with dust when working in dusty areas.
• A stud finder to locate wooden or steel studs in the walls.
• A simple continuity tester or multitester.
• A comfortable pair of work gloves.
• A sturdy stepladder, preferably one made of nonconductive materials.
• A tool belt with appropriate loops and pouches for the tools you use most.
• Two-way radios or walkie-talkies. They are indispensable for pulling or testing over even moderate distances or between floors. Invest in the hands-free models that have a headset, and you'll be glad you did.
• Extra batteries (or recharging stands) for your flashlights, radios, and cable testers.

Tip

Here's an installation tip: Wall-outlet boxes are often placed one hammer length from the floor, especially in residences (this is based on a standard hammer, not the heavier and longer framing hammers). It's a real time-saver, but check the boxes installed by the electricians before you use this quick measuring technique for installing the data communications boxes so that they'll all be the same height.

A multipurpose tool is also very handy. One popular choice is a Leatherman model with a coax crimper opening in the jaws of the pliers. It's just the thing for those times when you're on the ladder looking down at the exact tool you need lying on the floor where you just dropped it.

One of the neatest ideas for carrying tools is something that IDEAL DataComm calls the Bucket Bag (pictured in Figure 1). This bag sits over a five-gallon bucket and allows you to easily organize your tools.

Figure 2: IDEAL DataComm's Bucket Bag