First, RJ45 and RJ11 crystal head
1, RJ45 crystal head
We usually refer to the network crystal head refers to the RJ45 crystal head, which is a connector with 8 pins, mainly used in Ethernet, "RJ" means registered jack, "45" means interface standard Serial number. The RJ45 crystal head is usually terminated on an Ethernet cable and used to connect various network devices such as computers, routers, switches, etc.
2, RJ11 crystal head
The four-core crystal head used in the telephone line is the RJ11 crystal head, which is similar to the RJ45 crystal head, but has only four pins. It is a connector developed by Western Electronics, which is commonly used to connect telephones and modems. It should be noted that the RJ11 usually refers to a 6-position (6-pin) modular jack or plug, but only 4 pins are used. In addition, the RJ11 is also used in the 4-pin version of the modular connector.
3, the difference between RJ45 crystal head and RJ11 crystal head
The RJ45 crystal head is a connector with 8 grooves and 8 contacts (8p8c), while the RJ11 crystal head usually has only 6 grooves and 4 contacts (6p4c). Therefore, the RJ45 crystal head is larger than the RJ11 crystal. big head. The RJ11 crystal head can usually be inserted into the RJ45 interface, but not vice versa, but it is strongly recommended not to use the RJ11 crystal head for the RJ45 interface.
Different line order standards
Due to the different construction of the RJ45 crystal head and the RJ11 crystal head, the wire sequence standard for wiring is also different. The RJ11 crystal head generally has only 6 grooves and 4 contacts (6p4c), and its wire sequence is fixed.
There are two line order standards for RJ45 crystal head wiring: T-568A and T-568B. By adopting different standards, the resulting network cable has two types: straight-through type and cross-type. Now all the network cable production is 568B, the line sequence is as follows:
Orange white / orange / green white / blue / blue white / green / brown white / brown