Phone systems – Key vs PBX

For small to medium businesses, there are two types of phone systems: Key systems and Private Branch Exchanges (PBXs). Large phone systems only use PBXs.

If you have a single incoming phone line or a few phone lines, you probably have a Key system. The most obvious characteristic about a Key system is that you have a ‘line’ button for each phone line. Many times, the phone number is listed on the button. Other times, the phone will be labeled ‘line 1’, ‘line 2’, etc. The phone company provides ‘roll over’, a feature that when the line is being used and another call comes in on that number, it ‘rolls over’ to the next line number. The Key system is very restricted. Most of the features are controlled by the phone company. The business pays a premium for ‘business’ phone lines. But some features (ex: call forwarding, voice mail) are now included in residential phone lines. 

One of main issues with Key systems is that most are proprietary. Even within a given manufacture, you can only buy the specific phones designed for that Key switch. Upgrading is a matter of removing all of the old system and replacing every piece with the new system.

The PBX moves many of those features to the local phone system. Call forwarding, ring pattern, phone line management are all handled locally. And there are some differences. The ‘line’ button does not tie you to a specific line. The phone lines are in a pool. When you make a call, it grabs the first available. Likewise, your phone number isn’t tied to a single line. It can handle a few or a bunch of concurrent calls.

The older PBXs are the same as Key systems. They can’t be upgraded and you are limited to specific phones and devices that will work with the PBX.

Over the years, the cost of technology has improved to the point that PBXs are more open (some more than others), affordable and feature rich. 

At Farsight VDS, we only support one PBX, 3CX phone systems.  Not the cheapest but far from the most expensive, 3CX supports numerous brands of phones and phone devices.  When you are ready to upgrade or install a new phone system, give us a call. We’ll be happy to visit with you.