# IP PBX
> A PBX that uses Internet Protocol for voice transmission instead of traditional circuit switching

An IP PBX routes calls using Internet Protocol rather than traditional telephone switching.

## What is an IP PBX?
An IP PBX (Internet Protocol Private Branch Exchange) is a private telephone network that uses [VoIP](/voip-glossary/voip/) technology to route calls over IP networks instead of traditional circuit-switched telephone lines. It can be deployed on-premise or as a [Cloud PBX](/voip-glossary/cloud-pbx/).

## IP PBX features
Modern IP PBX systems offer call routing, voicemail-to-email, conferencing, [IVR](/voip-glossary/ivr/), call recording, and integration with CRM and business tools. They connect to the PSTN via [SIP trunks](/voip-glossary/what-is-sip-trunking/).

## Related Terms
- [PBX](/voip-glossary/pbx/)
- [Cloud PBX](/voip-glossary/cloud-pbx/)