How to connect network module to RJ45 crystal head

568A and 568B Terminals
The most famous feature of ANSI/TIA-568 is the wiring system for the pin/pair distribution of eight-conductor 100-ohm balanced twisted pair cables, which are divided into TIA/EIA-568-A line sequence and TIA/EIA-568-B line sequence. The specific connection methods are detailed in the table below.

The line sequence of T568A is: white-green, green, white-orange, blue, white-blue, orange, white-brown, brown

The line sequence of T568B is: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown

Each pure color line and its corresponding colored line (such as white-orange, orange) form a pair of differential transmission lines.

Tip and Ring refer to the two wires that make up the telephone wiring circuit. Tip is another name for the positive wire; Ring is another name for the negative wire. The TIP line voltage is positive voltage, and the RING is negative voltage, and the voltage between them is generally 48V.

Tip means "top, tip", and ring means "ring". The original telephone was a magnet telephone, with manual connection. The operator used a 6.5mm plug (similar in shape to today's headphone plugs). The top metal of the plug was the tip, and the metal ring at the back was the ring.

Different cables with different connectors at both ends

Straight-through cable: used to connect switching equipment and terminals (self-understanding: different types of equipment?), the line sequence of the line ends uses the same line sequence. (Note: Under normal circumstances, use the T568B standard!)

Crossover cable: used to connect devices of the same type (between switching devices or between terminals). The cable ends use two line sequences (one end uses line sequence A and the other end uses line sequence B).

However, many switch ports are adaptive to line order, and crossover cables are rarely used. (The so-called adaptive generally means that straight-through cables and crossover cables can be automatically flipped, and the speed mode and duplex mode are automatically selected according to the other party's connection method.)

RJ45 connection signal
In Fast Ethernet (10/100M Ethernet), only four wires 1, 2, 3, and 6 are used to reduce electromagnetic interference by differential signal transmission. 1 and 2 are TX (transmit) (twisted together), and 3 and 6 are RX (receive) twisted together.

Therefore, a parallel cable means that both ends are EIA-568-A or EIA-568-B, while a jumper cable is a connection method that uses EIA-568-A at one end and EIA-568-B at the other end.

In Gigabit Ethernet (1000M Ethernet) or Power over Ethernet (PoE), all four differential pairs are used.

Special attention:

No-punch network module: Generally, the T568B line sequence is used. Just insert the wires of the corresponding colors strictly according to the wire colors marked on the module groove. (Although the "actual line sequence of the wires" at the module terminal may not be consistent with the usual T568B line sequence, due to the jumper inside the no-punch module, it has actually been converted to the normal T568B line sequence: white-orange, orange, white-green, blue, white-blue, green, white-brown, brown.)

other:

In addition: If you only use 4 of the 8 network cables, the network speed will definitely be affected. For example: if you use a network cable and do not directly split it through a router or hub, but directly connect (or use a simple 1-to-2 splitter) to split it into 2 network cables, the 200M network speed will drop to 100M. You need to verify: is it a 50% reduction, or is the maximum transmission speed of the 4-wire network cable 100M?