Twisted Pair Cable
Guided metallic transmission media. Twisted pair cable is a form of wiring in which two conductors are twisted together for the purposes of canceling out electromagnetic interference (EMI) from external sources and crosstalk from neighboring conductors.
Unshielded Twisted Pair Cable UTP
Unshielded Twisted Pair (UTP) is a set of three or four pairs of wires twisted around the other to prevent EMI electromagnetic interference.
It is less expensive.
Easier to install.
UTP comes in the form of Cat 2, 3, 4, and 5 grades.
Shielded Twisted Pair Cable STP
Shielded Twisted Pair has four pairs of wires with each wire in each pair twisted together. STP is surrounded with a foil shield and copper braided around the wires that allows more protection from any external electromagnetic interference.
The cable is physically larger and more difficult to install.
More expensive than UTP.
Why Pairs are twisted
Electromagnetic Interference (EMI) is the disruption of operation of an electronic device when it is in the area of an electromagnetic field. The source may be any object, artificial or natural, that carries rapidly changing electrical currents.
In order to eliminate EMI effect twisted pair approach is used.The wires twisted with and along each other carry equal and opposite amount of current through them. Therefore, the interference/noise produced by one wire is cancelled by the interference/noise produced by other wire since they are equal and opposite in nature.
Registered jack (RJ) is a standardized physical network interface for connecting telecommunications or data equipment. The most common twisted-pair connector is an 8-position, 8-contact (8P8C) modular plug and jack commonly referred to as an RJ45 connector.
Wiring schemes T568A and T568B are used to terminate the twisted-pair cable onto the connector interface.
A rolled or rollover cable is used to manage a router or switch from the console port of that device. This cable is usually used when configuring one of these devices for the first time.