RJ45 is a type of information socket (ie, communication terminal) connector in the wiring system. It is commonly used in DTE (data terminal equipment) type of Ethernet network card, router Ethernet interface,and DCE (digital communication equipment) for switches, such as connecting network devices such as computers, routers, and switches.
RJ11 and RJ45 are very similar, but only have 4 pins (8 pin for RJ45). It is often used to connect modem modems and phones In computer systems.
Since RJ45 and RJ11 are very similar, what is the difference between them?
First: Construction is different
The RJ45 conenctor is with 8 grooves and 8 contacts (8p8c); the RJ11 conenctor usually has only 6 grooves and 4 contacts (6P4C). Therefore, the RJ45 conenctor is larger than the RJ11 connector.
Second: the line order standard
The RJ11 connector generally has only 6 grooves and 4 contacts, and its line sequence is fixed, as shown below:
The RJ45 conenctor has two line order standards, namely T-568A and T-568B. The corresponding line sequence from pin 1 to pin 8 is:
T-568A：White green、green、white orange、blue、white blue、orange、white brown、brown
T-568B：white orange、orange、White green、blue、white blue、green、white brown、brown
Different standards are usually used, and the final cable is made of straight-through and cross-type. If you want to make a straight-through cable, both ends of the cable can be wired according to the same standard (T-568A or T-568B). If you want to make a crossover cable, both ends of the cable should be wired with different standards.
Third: the conenctor interface size
Physically, the RJ11 interface is slightly smaller than the RJ45 interface, which makes it easy to think that they can work together, but actually not.Because RJ11 is not internationally standardized, its size, insertion strength, angle, are not uniformly in accordance with international standard connector design requirements, so it cannot be ensured to be interoperable, and forced use may even cause damage to both. Be sure to distinguish clearly in actual use.