This is an Illustration of a Hybrid cloud
This can be with multiple sites using VPN or MPLS.  The main headquarters is at DVX, Inc. Data Center which houses the Server which is virtualized on VMWare .  The Server also has a secondary server for resiliency which can also be located at the remote location.  There is also the ability to add a gateway to support both Digital and Analog trunks along with the ability for Digital and Analog end points as well.  Optional components include Fax servers, Paging equipment and a Call Center Server to name a few.