A crossover cable connects two devices of the same type, for example DTE-DTE or DCE-DCE, usually connected asymmetrically (DTE-DCE), by a modified

cable Cable may refer to: Mechanical * Nautical cable, an assembly of three or more ropes woven against the weave of the ropes, rendering it virtually waterproof * Wire rope, a type of rope that consists of several strands of metal wire laid into a hel ...

called a crosslink. Such a distinction between devices was introduced by

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. The crossing of wires in a cable or in a connector adaptor allows: * connecting two devices directly, output of one to input of the other, * letting two terminal (DTE) devices communicate without an interconnecting hub knot, i.e. PCs, * linking two or more hubs,

switches In electrical engineering, a switch is an electrical component that can disconnect or connect the conducting path in an electrical circuit, interrupting the electric current or diverting it from one conductor to another. The most common type o ...

or routers (DCE) together, possibly to work as one wider device. In contrast, a straight-through cable uses direct wiring to connect complementary devices, e.g. a PC to a switch.

Concept

Straight-through cables are used for most applications, but crossover cables are required in others. In a straight-through cable, pins on one end correspond exactly to the corresponding pins on the other end (pin 1 to pin 1, pin 2 to pin 2, etc.). Using the same wiring scheme at each end yields a straight-through cable (a given color wire connects to a given number pin, the same at both ends). In this case, the terminations are identical, so only one pinout is required. In a crossover cable, pins do not correspondsome or all of the conductors are swapped at the terminations. For example, if pin 1 on one end goes to pin 2 on the other end, then pin 2 on one end goes to pin 1 on the other end, and the other pins remain unaffected. Such crossover cables are electrically symmetrical, meaning that they work identically regardless of which way you plug them in (if you turn the cable around, it still connects the same pins as before). Using different wiring at each end yields a crossover cable (a given color wire connects to one number pin at one end, and a different number pin at the other).

Examples

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Ethernet crossover cable An Ethernet crossover cable is a crossover cable for Ethernet used to connect computing devices together directly. It is most often used to connect two devices of the same type, e.g. two computers (via their network interface controllers) or two ...

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* A

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is a type of degraded "one side crosslinked connection" connecting a port to itself, usually for test purposes.

Other technologies

Some connection standards use different

balanced pair In telecommunications and professional audio, a balanced line or balanced signal pair is an electrical circuit consisting of two conductors of the same type, both of which have equal impedances along their lengths, to ground, and to other c ...

s to transmit data, so crossover cables for them have different configurations to swap the transmit and receive pairs: * Twisted pair

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uses T568B pairs 1 and 3 (the same as T568A pairs 1 and 2), so a crossover cable to connect two Token Ring interfaces must swap these pairs, connecting pins 4, 5, 3, and 6 to 3, 6, 4, and 5 respectively. * A T1 cable uses T568B pairs 1 and 2, so to connect two T1 CSU/DSU devices back-to-back requires a crossover cable that swaps these pairs. Specifically, pins 1, 2, 4, and 5 are connected to 4, 5, 1, and 2 respectively. * A 56K DDS cable uses T568B pairs 2 and 4, so a crossover cable for these devices swaps those pairs (pins 1, 2, 7, and 8 are connected to 7, 8, 1, and 2 respectively).

References

{{DEFAULTSORT:Crossover Cable Signal cables

Concept

Examples

Other technologies

See also

References