This interactive voice response (IVR) diagram sample shows how does the hosted PBX work. It was designed on the base of the Wikimedia Commons file: Hosted pbx.jpg. [commons.wikimedia.org/wiki/File:Hosted_pbx.jpg]
This file is licensed under the Creative Commons Attribution-Share Alike 3.0 Unported license. [creativecommons.org/licenses/by-sa/3.0/deed.en]
"A private branch exchange (PBX) is a telephone exchange or switching system that serves a private organization and performs concentration of central office lines or trunks and provides intercommunication between a large number of telephone stations in the organization. ...
Virtual PBX systems or hosted PBX systems deliver PBX functionality as a service, available over the public switched telephone network (PSTN) or the Internet. Hosted PBXs are typically provided by a telephone company or service provider, using equipment located in the premises of a telephone exchange or the provider's data center. This means the customer does not need to buy or install PBX equipment. Generally the service is provided by a lease agreement and the provider can, in some configurations, use the same switching equipment to service multiple hosted PBX customers." [Business telephone system. Wikipedia]
The IVR diagram example "Hosted PBX" was designed using ConceptDraw PRO diagramming and vector drawing software extended with the Interactive Voice Response Diagrams solution from the Computer and Networks area of ConceptDraw Solution Park.