H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 63)

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Ethernet twisted pair cable
Introduction
An Ethernet twisted pair cable consists of four pairs of insulated copper
wires twisted together. Every wire uses a different color, and has a
diameter of about 1 mm (0.04 in). A pair of twisted copper cables can
cancel the electromagnetic radiation of each other, and reduce
interference of external sources. An Ethernet twisted pair cable mainly
transmits analog signals and is advantageous in transmitting data over
shorter distances. It is the commonly used transmission media of the
Ethernet. The maximum transmission distance of the Ethernet twisted pair
cable is 100 m (328.08 ft). To extend the transmission distance, you can
connect two twisted pair cable segments with a repeater. At most four
repeaters can be added, which means five segments can be joined
together to provide a transmission distance of 500 m (1640.42 ft).
Ethernet twisted pair cables can be classified into category 3, category
4, category 5, category 5e, category 6, and category 7 cables based
on performance. In LANs, category 5, category 5e, and category 6 are
commonly used.
Table 20 Description of commonly used Ethernet twisted pair cables
Type Description
Category 5
Suitable for data transmission at a maximum speed of 100
Mbps
Category 5e
Suitable for data transmission at a maximum speed of 1000
Mbps
Category 6
Suitable for data transmission at a speed higher than 1
Gbps
Based on whether a metal shielding is used, Ethernet twisted pair cables
can be classified into shielded twisted pair (STP) and unshielded twisted
pair (UTP). An STP cable provides a metallic braid between the twisted
pairs and the outer jacket. This metallic braid helps reduce radiation,
prevent information from being listened, and eliminate external
electromagnetic interference (EMI) of external sources. STPs have strict