The Difference Between RJ-45 and RJ-11 Cables

If you’re going to start migrating to an internet phone service, you need to be able to speak plainly and efficiently about the hardware involved. The cables at the back of your computer all have names, but two of them are the most important to know for anyone who is using a VoIP phone and a computer: RJ-11 and RJ-45.

So what are these two cables and what should you know about them for your business?

What Is “RJ”?

RJ means “registered jack”, and 11 and 45 are the numbers associated with these two cables. The RJ-11 is the smaller of the two, while both are made of plastic with the easily-recognizable clear plastic end. These cables are responsible for transmitting data from your devices to various networks. But the two have very important differences.

Differences Between RJ-45 and RJ-11

  • Pins: When you look at the pins at each end of the two cables, you’ll find that the RJ-11 has a smaller end and only four pins. The RJ-45 has eight pins and is wider.

  • Location: An RJ-45 cable is used for high-speed internet connections and is more commonly used now. RJ-11 cables are for dial-up modems and traditional phone systems.

  • Socket: Because of the size difference, you can’t force an RJ45 into the receptacle meant for the RJ-11 but you can do the inverse. If you force your system to use an RJ-11 on an RJ-45 receptacle, you’re running a risk of damaging the network adapter of the computer.

The Best Way to Get All Your Cables Connected

  • Want to know which cable should go where in your business telephone system? Give us a call at Nebula Solutions at (937) 387-2948 for a free consultation and quotation on how much you need for a new phone setup, saving you money, time, and manpower.