How a PBX works
The PBX sits between the internal company network and the public telephone network. Calls within the company go directly through the exchange without charges to the operator. External lines, for example SIP trunk or previously ISDN, are shared by all extensions together.
The PBX ensures:
- routing incoming calls to the correct branch or group
- call forwarding and hold on the line
- conference calls without the need for an external bridge
- automatic voice menu (IVR) for greeting and routing callers
What a PBX system does for a company
Every company with multiple employees receiving calls via a PBX benefits. Calls between extensions are free, and the company presents itself externally with one main number, even if it has dozens of lines.
- Voice mailbox for every employee or department
- Call queue instead of a busy tone when the line is congested
- Group calling - incoming calls ring on multiple phones simultaneously
- Redirecting if not answered on a mobile number or by a colleague
- Call recording for quality control or archiving purposes
Traditional PBX versus cloud-based exchange
A traditional PBX is physical equipment that the company purchases, installs and manages itself. It requires a technical administrator, software licences and regular maintenance. In the event of a fault or capacity expansion, an on-site technician intervention is necessary.
Cloud PBX It runs on the provider's servers. The company pays a monthly fee, does not manage hardware, and performs configuration via a web interface. Adding a new branch takes minutes. On virtualni-ustredna.cz you can set up branches and routing rules yourself without technical knowledge.
Frequently Asked Questions
What is the difference between a PBX and a private branch exchange?
PBX and a private branch exchange are synonyms. PBX is the English term (Private Branch Exchange), while pobočková ústředna is its Czech translation. Both terms refer to the same device or service.
Do I need physical hardware for a PBX?
Traditional PBX requires hardware located on the company premises. A cloud-based PBX operates entirely without your own equipment, everything runs on the provider's servers and you access it via a web browser.
How many PBX branches can be serviced?
Cloud-based PBX systems typically have no fixed limit on the number of extensions. Extensions can be added continuously without changing the infrastructure. With physical PBX, capacity depends on the specific device model.