Indoor Phone Wire: Category Phone Cable

Indoor phone and data cable is manufactured in multiple styles, sizes and pair counts. This brief article is used to explain the similarities and differences between the different categories of indoor phone wire.

These twisted paired telephone cables are designed for high signal integrity. In other orders, they transmit phone and data signals such as Ethernet. Indoor phone cable is manufactured in solid, stranded, PVC, plenum and shielded and non-shielded constructions. The vast majority of indoor phone cable is 24 awg.

There are multiple categories of indoor phone cable. In the past, Category 3 was the most advanced with a possible bandwidth of 16 MHZ. Today, many applications require a cable with a higher bandwidth so many opt for Category 5, 5 enhanced or 6. That is where Cat 5, 5e and 6 come in to play. They run at 100 MHZ or higher making the transfer of voice and data faster and more reliable. However, it is worth noting that these higher rated categories rarely are manufactured in higher pair counts (over 50) and they do not allow longer cable distances for Ethernet networks.

The vast majority of Cat 5, 5e and 6 sold today is in a 4 pair construction. You will see Cat 6 using a 23 awg size in lieu of 24 awg. Millions of feet of indoor phone wire is sold daily throughout the world in all types of constructions. While most indoor phone cable is a commodity, certain high pair counts or unique constructions would make it a specialty cable and often hard to find.

A popular question regarding indoor phone/data cable is what makes one category faster or more reliable than the other?

There is not one answer to that question. Many factors help determine this. One is the type of insulation. Certain insulations like FEP have better electrical characteristics. Another is the twisting of the cable. The more intimating twisted a phone cable, the higher the category. For example, a standard cat 5 cable has 3 twists per inch while a cat 3 cable has approximately 6 twists per inch. Even the bonding agent used to hold the pairs together can affect the cables integrity.

The goal to changing the construction of the phone cable is simple – To have a faster more reliable cable that eliminates noise and crosstalk. Many manufacturers offer what they call cat 6 Plus or even Cat 7 boasting of MHZ over 600. The reality is a level 5e or 6 is typically plenty on today’s structured cabling set-ups for computer networking.

A simple way to identify someone’s needs for indoor phone cable is to find out how many pairs are needed, PVC or plenum construction and required category level or MHZ.