RJ45 through connector is a plastic connector that can only be inserted in a fixed direction and automatically prevents it from falling off, commonly known as "crystal head", the technical term is RJ45 connector (RJ-45 is a network interface specification, similar to RJ-11 The interface is the "telephone interface" we usually use to connect the telephone line). The reason why it is called "crystal head" is because of its crystal clear appearance. This rj45 through connector must be installed at both ends of the twisted pair so that it can be plugged into the RJ-45 interface of the network card (NIC), hub (Hub) or switch (Switch) for network communication.
The RJ11 interface is very similar to the rj45 through connector, but only has 4 pins (8 for RJ45). In computer systems, RJ11 is mainly used to connect modem debugger. In everyday applications, RJ-11 is commonly found in telephone lines. There is also a kind of RJ12 that is usually suitable for voice communication. It has the same structure as the first two, but has six pins (6p6c). At the same time, two types of six-slot four-needle (6p4c) and six-slot two-needle (6p2c) were derived.
Regarding the crystal head stranded wire, the color code and arrangement method of the rj45 through connector are strictly regulated by a unified international standard, so just remember the standard when doing it. TIA/EIA568B is commonly used now.
There are two types of rj45 through connector twisted-pair cables: one is a widely used straight cable, and the other is a crossover cable used in special cases, if the PC is connected to a switch or other network interface, etc., or both sides of other connections If the status is not equal, use a straight connection cable, and if the two connected devices are equal, such as two PCs, notebooks, etc., you must use a crossover cable. The difference between the two is that the line sequence is inconsistent , the interface is the same.