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If not please explain the difference in terms of usage

2 Answers 2

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Twisted Pair refers to the cable itself. Two conductors inside the cable are wound round each other to cancel out electromagnetic interference. A Twisted Pair cable could carry all kinds of signals.

A Crossover Cable refers to how the contacts in the cable connectors are connected to the wires at each end of the cable. In this case the connectors are connected asymmetrically so you can do things like connect the input of one device to the output of another (which a "straight-through" cable would not normally do). A common case is an Ethernet Crossover Cable which allows you to connect two ethernet ports on two systems directly together without using a hub or switch; this works because some pin assignments are swapped from one end of the cable to the other.

Ethernet cables are usually UTP so a crossover cable will be a twisted pair cable, but so would an ordinary ("straight-through") ethernet cable. The two things are not related directly.

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  • so this means that straight through cables cannot be used to connect two devices?
    – user39966
    Oct 28, 2010 at 12:03
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    Sometimes they can be, it depends on the ethernet port. Some ports will automatically configure themselves to work appropriately as part of the auto-negotiation process. homepage.ntlworld.com/robin.d.h.walker/cmtips/…
    – David Webb
    Oct 28, 2010 at 12:06
  • This autonegotiation is referred to as Auto-MDIX. Oct 29, 2010 at 3:24
  • user39966: It depends on what the devices ARE. Historically you would use a straight-through (s-t) cable to connect a computer to a port on a switch or a hub, and a x-over cable to connect computer to computer. To connect one port on the switch to a port on an "upstream" switch you would either use a x-over, or put one of the ports in question into crossover (MDI-X) mode and use a s-t cable. Older switches and hubs had one port with a physical switch for this purpose. Most modern switches (and some computer NICs too) implement auto-MDI-X so they will automatically take care of this. Sep 15, 2014 at 21:42
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Twisted pair is the type of cable, crossover is a type of way twisted pair can be wired up at the jacks.

Crossover cables are made of twisted pair cable, so are straight-through cables.

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