Ethernet cables come in different forms or categories (called “Cat,” for short). Cable categories are numbered from 1 through 8, and each Cat denotes a different level of performance in signal bandwidth, attenuation, and crosstalk. While there are Cats 1 through 4, they are obsolete. The lowest Cat standard recommended is Cat 5, and as the internet keeps getting faster, Cat 5 is on its way to becoming obsolete, too.
The categories now in use are as follows:
- Cat 5: An older form of Ethernet cable which enables speeds of 10/100 Mbps (megabits per second). While there is still some legacy equipment using Cat 5, it is currently considered to be all but obsolete.
- Cat 5e: An updated version of Cat 5 that operates at 10/100/1000 Mbps speeds.
- Cat 6: Enables speeds up to 10 Gbps (Gigabit per second) at 250 MHZ (megahertz) with less crosstalk. However, 10 Gbps speed is only effective up to 164 feet.
- Cat 6a: An improved version of Cat 6, Cat 6a supports speeds up to 10 Gbps at 500 MHz to 328 feet. This cable offers twice the bandwidth of Cat 6.
- Cat 7: Offers up to 10 Gbps up to 100 meters (328 feet). It performs similar to Cat 6a cable but supports transmission frequencies up to 600 MHz and has shown in lab tests to transmit up to 40 Gbps at 50 meters (approximately 164 feet) and 100 Gbps at 15 meters (about 49 feet). Cat 7 cable is best suited for data centers and large enterprise networks.
- Cat 8: Supports speeds of 40 Gbps at 2000 MHz bandwidth. These cables are specially designed for data centers and are pretty expensive.