CAT5e or CAT6? Which do you need?

We install a lot of networking cable for our clients in and around the Indianapolis area. In the early phases of planning clients often ask whether they should purchase CAT5e vs CAT6 cabling. The answer to this question is different for each customer’s application.  Some important factors to consider when choosing the correct cable are: What will the cable be used for? How long are the cable runs going to be? What type of information will pass across the cable and will speed be of importance? Lastly, what type of environment is the cable being installed in?

Before you make a decision about what type of cable will be best for your application let’s take a minute and actually look at a few different versions of telephone and data wiring so you can see how cabling has evolved over the years. Category 3 wiring also referred to as CAT3 was popular when introduced in 1990 and was used for telephone communications as well as computer networking, but would only achieve a speed of 100mbit/s. CAT 3 wiring quickly lost its popularity when CAT 5 and CAT5e cabling were introduced in early 2000. This opened the door for businesses to send and receive data at much quicker speeds.

The main difference between CAT 5 and CAT 5e is speed and reliability. CAT 5 supports speeds of up to 100mbps. CAT5e supports 1000mbps or “gigabit” speeds. It also cuts down on crosstalk. Crosstalk is the interference you sometimes have between wires inside the cable.  In recent years Category 6 cable has been introduced. The improvement here is speed and reliability. It is capable of transferring data at  speeds of 10-gigibit and extra interference improvements were also made. What makes CAT6 different than CAT5e? The three biggest differences between CAT5e and CAT6 cabling is how it is physically constructed. CAT6 features larger conductors, a tighter twist rate, and often a center core or separator. The result of these changes in design are a cable that offers much faster transfer speeds, is more resistance to interference (internal and external), is less affected by changes in temperature, and is less prone to errors.

Now that you have some basic knowledge of network cabling lets break down a few main categories and help you make the best decision. There are a lot of factors that go into determining what type of cabling should be used for specific applications.

Function Function of the cable, what type of device will run on this cable. For traditional business telephones CAT5e is all that is needed. There would be no advantage to using CAT6 with a phone. In regards to network equipment the thing to keep in mind is if you installed CAT6 cabling are you truly gaining anything? We know that CAT6 can transfer data at higher speeds but the real question is will the network equipment send the data at speeds about 1000mbps. If the answer is no there would be no benefit from using CAT6.

Speed When we think about advances in cabling we most likely think about speed. It is important to have cabling that is equivalent to what is running on it. For example, if you have a data switch that supports speeds in excess of gigabit but only had CAT5e cabling, you would not be getting the most out of your data switch.

Distance CAT5e and CAT6 both have a maximum length of 328 feet. It is recommended to keep the runs to 295 or less when using patch cords. Should circumstances arise where devices are needed further than 328 feet away you would want to consider installing a network cable extender or a data switch to shorten the run.

Cost In reality, the cost difference between CAT5e and CAT6 cable comes out to be a very small portion of the total network budget once you consider all the other equipment (Racks, servers, switches, routers, etc) involved in the installation. Rather than focus on cost we encourage our customers to focus on the more important factors. How busy the network is going to be? How many devices will be on it? Will there be extreme temperatures or temperature changes? Will there be other cabling running nearby? The added cost could potentially save you money in the long run. As technology continues to change and devices are sending and receiving data at a quicker pace the need for CAT6 wire is closer then you might think.

Environment This may be the most important category of all. What type of cable does your building require; Plenum (also referred to as Teflon) or NonPlenum (also referred to as PVC)? Plenum rated cable is specifically insulated with low smoke and low flame characteristics. Plenum rated cable is required in any air handling space. For example, most office buildings with a drop ceiling use the ceiling to return air to the AC unit. To be sure you choose the correct cable it is recommended to check with your building manager. Plenum rated cable is about 15% more expensive than standard PVC cable.

Temperature and Electrical A study conducted by The Nexans Data Communications Competence Center (DCCC) found that electrically noisy environments or environments with extreme temperatures or temperature changes had the greatest affect on network performance. The DCCC directly compared CAT5e and CAT6 cables in such environments. The article summarizing that study can be found here.