A private branch exchange routes internal calls between extensions in an office and connects them to the external public telephone network using shared trunk lines. It allows an organization to operate hundreds of desk phones without leasing individual outside lines for every employee. Early systems relied on physical switchboards and relays, whereas software versions route voice traffic over IP networks.
Heard on the job
We need to reprogram the private branch exchange to route all after hours calls to the answering service.
Also heard as
- PBX