Choosing A Business Telephone System Here are some of the things to consider 1. What is the maximum number of extensions it can handle WITHOUT having to replace the "PBX on the wall"?Check the capacity on the system you are purchasingDo you need a larger system in the range to get maximum capacity stated?Find out at what stage you will need to invest in a bigger boxGet this information in writing!!! 2. How will it help our customers...... Similar Editorial : Choosing an Exhaust System by Tim Piscitelli. | Source : Slider Phone