Classes for Twisted Pair Cabling

The ISO/IEC 11801 defines four classes for twisted pair cabling. These classes are based on the maximum frequency required for the application and is summarized as follows:

Class A: speech band and low frequency applications up to 100 KHz; it involves to Category 1 components and supports basic rate ISDN

Class B: low to medium bit rates for applications up to 1 MHz; based on use of Category 2 components and supports applications such as such as primary rate ISDN

Class C: medium data rate applications up to 16 MHz; utilizing Category 3 components and supports applications such as 10 Mbps Ethernet as used in 10 BASE T LAN’s

Class D: high data rate applications up to 100 MHz; utilizing Category 5e components and supporting applications such as 100BASE TX (100 Mb/s) and Gigabit Ethernet (l000Mb/s) LAN’s and ATM transmission @ 155 Mb/s

Class E: higher data rate applications using up to 250MHz of Bandwidth; and using Category 6 components.

Class F: higher data rate applications using up to 600MHz of bandwidth; and using Category 7 components.