Constructing Cables

Pins: Slots within RJ45 connectors where wires can be place and then punched down to lock them in. You must configure pins in a specific order for them to function properly.

Cables have 8 pins, which connect the two ends of a cable through 8 brightly colored wires.  

TIA cabling has 2 standards, T568 A and B. The difference between the two standards is the order in which the anatomy of the cables align. 

They are functionally the same, but you need to make sure that you stick to a single standard throughout all your cables.

A Straight-Through cable is when the two ends of a cable correlate 1:1, meaning pin slot #1 on one end of a cable is connected to pin slot #1 on the other end of the cable

A Crossover cable follows a bit more of a complicated pattern in which some of the cables cross over to other cables. You do not need to memorize this specific order.

Straight-through cables will be used to connect different types of hosts to each other. This means that whenever you are connecting a computer to a router, a router to a switch, and so on, you will have to use a straight-through cable for the hosts to communicate with each other. 

A crossover cable covers the other situations where you are connecting the same device type to each other. This is used to connect to computers to each other. 

Uplink ports are used to connect a virtual switch to a physial switch. With uplink ports, you use Straight-Through cables. You can use a crossover cable to connect two switches in the case that the switches do not have uplink ports.

10BASE-T Ethernet only uses 4 pins

Pin 1: Transmit +

Pin 2: Transmit -

Pin 3: Receive +

Pin 6: Receive -

Pins 4, 5, 7, and 8 are unused.

Power over Ethernet cabling allows one to transmit ethernet on the first 4 pins while transmitting electrical power on the other unused pins.