rj11 plug and RJ45 interface is very similar, but only 4-pin (RJ45 to 8). In a computer system, rj11 plug main modem for 24 port patch panel the modem. RJ11 generally refers to the position 6 (6 pin) modular jack or plug. This connector is no international standard and is mentioned in the rj45 keystone jack cabling standard. Moreover, the name often used for the 4-pin version of the modular connector, causing confusion.