Different Category of Ethernet Cable

The EIA/TIA (Electronic Industries Association and the newer Telecommunications Industry Alliance) is the standards body that creates the Physical layer specifications for Ethernet. Each Ethernet cable type that is specified by the EIA/TIA has inherent attenuation, which is defined as the loss of signal strength as it travels the length of a cable and is measured in decibels (dB). The cabling used in corporate and home markets is measured in categories. A higher quality cable will have a higher-rated category and lower attenuation.

Category of Ethernet Cable

There are following categories of Ethernet Cable available based on the their quality.

Category 3:

It is commanly known as Cat 3 or Station Wire. It is used for voice cabling and 10 Mbps Ethernet with a possible bandwidth of 16MHz. Cat 3 is used in Telephone Wiring. It is used earlier in Computer Networking for 10BaseT Ethernet, Token Ring or ATM 25 Network.

Category 4:

It is also used in Telephone Network to transmit voice and date at 16 Mbit/s. It is used in Computer Networking for some Token Ring, 10BaseT and 100BaseT4 Ethernet.

Category 5:

It is currently an outdated standard that provides support for up to 100Mhz operation. It can be used for 10/100 Ethernet without worry, however for longer runs of 1000 Mbps it is recommended to use Cat 5e or higher. It is suitable for  10BaseT, 100BaseTX(Fast Ethernet) and 1000BaseT \(Gigabit Ethernet).

Category 5e:

It is an enhanced version Cat 5 cabling that helps to prevent cross-talk. Category 5e cable provides support for frequencies up to 100Mhz. Cat 5e generally provides the best price for performance, however for future proofing Cat 6 or higher might be a better choice as it usually does not cost much more.

Category 6:

Like Cat 5e but with larger gauge wires, works for 10/100/1000 Mbps. This cable is better than Cat 5e for Gigabit Ethernet. Compared with Cat 5 and Cat 5e, Cat 6 features more stringent specifications for crosstalk and system noise. The cable standard provides performance of up to 250 MHz and is suitable for 10BaseT, 100BaseTX (Fast Ethernet), 1000BaseT/1000BaseTX (Gigabit Ethernet) and 10GBaseT (10-Gigabit Ethernet).

Note: 

• If Cat 6 rated patch cables, jacks and connectors are not used with Cat 6 wiring, overall performance is degraded to that of the cable or connector.
• When used for 10/100/1000BaseT, the maximum allowed length of a Cat 6 cable is 100 meters or 328 feet.
• When used for 10GBaseT, Cat 6 cable's maximum length is 55 meters (180 ft) in a favourable alien crosstalk environment, but only 37 meters (121 ft) in a hostile alien crosstalk environment.

Category 6a:

Category 6a (or Augmented Category 6) worked at frequencies up to 500 MHz twice that of Cat 6. Category 6a performs at improved specifications, in particular in the area of alien crosstalk as compared to Cat 6 UTP (unshielded twisted pair), which exhibited high alien noise in high frequencies. When used for 10GBaseT, the maximum allowed length of Cat 6a cable is 100 meters ( or 330 feet) without electronic testing.

Category 7:

Category 7 is the informal name for Class F cabling defined by a different standards body than Cat 6a and lower. It supports frequencies up to 600Mhz and may support the upcoming 100Gbps standard. It is fully shielded cable.