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IEEE 802.3 100Base-T4

100Base-T4 is an Ethernet interface specification for Fast Ethernet over STP or UTP cable. 100Base-T4 specifies a transmission rate of 100 Mbit/s and the CSMA/ CD(100Base-T) access method over four conductor pairs (UTP, Cat. 3).

Three conductor pairs are used for data transmission and one conductor pair for collision detection. This method uses a coding with three levels, the 4T+ coding. Here, 8 bits each are converted into a six- digit code (8B/6T coding). Each code group is transmitted separately on one of the three data lines, resulting in a data rate of 33.3 Mbps. By using 8B6T coding, the transmission rate of 100 Mbit/s becomes a transmission frequency of 25 MHz, which can be transmitted over category 3 UTP cable or a cable with a higher category.

Physical interfaces of Fast Ethernet

Physical interfaces of Fast Ethernet

Configurations with 100Base-T4 can only be set up in a star configuration in point-to-point connections. The segment length is limited to 100 m due to the cable attenuation according to the cabling standard. The RJ45 connector is defined as the connection technology.

Englisch: IEEE 802.3 100Base-T4
Updated at: 01.04.2015
#Words: 168
Links: Ethernet interface, scheduled transfer protocol (GSN) (STP), unshielded twisted pair (UTP), cable, transmission rate
Translations: DE

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