With IP PBX systems, you are able to have your PBX onsite or hosted on the cloud.
Eliminate large old school PBX systems that no one knows how to manage from your business and take advantage of PBX software that can be installed on commodity hardware.
Or take the hosted route and completely eliminate the need for an onsite PBX server.
This also reduces utilities overheads and management as it can be all done remotely.
With the flexibility of cloud or onsite IP PBX systems, you get to choose where you want your phone system.