RJ45 vs RJ11

Introduction

RJ45 is mostly used with Ethernet cables while RJ11 is connecting to telephone units. RJ45 is bigger in size. You cannot plug – in the RJ45 cable connecter into an RJ11 jack/interface/port/slot, however, you can do the opposite. RJ11 connecters, typically used for telephone and ADSL Connection, can support speeds up to 24 Mbps.

 On the other hand, RJ45 connectors, used in Ethernet connections, can support much higher speeds. RJ45 cable uses electric current so it can be easier to catch on a fire lighting while fiber SEP module has no such problem. RJ45 8P8C connectors are not the best choice for solid copper Ethernet cable. RJ11 as discussed before widely used in analog telephony to connect the phone instrument and the cable. These connectors are used for both telecom and data networks. Specially if they have ever had to connect on Ethernet wire to router. 

The letters “RJ” stands for registered jack. A registered jack (RJ) is a standardized network interface for connecting voice and data telecommunication equipment. The RJ11 connector is used to terminate traditional PSTN telephone networks. The RJ11 connector has four pins and is used to terminate telephone cables. The RJ11 uses the center two connections out of the six available for wiring a single phone line. RJ45 is a more recent modular, self- securing and compact technology for connecting Ethernet.