telephony/asterisk/20 20.21.0p0 OpenBSD

Asterisk is a complete IP PBX in software. It provides all of the features you would expect from a PBX including many advanced features that are often associated with high end (and high cost) proprietary PBXs, such as Voicemail services with Directory, Call Conferencing, Interactive Voice Response, and Call Queuing.

Asterisk supports Voice over IP in many protocols, and can interoperate with almost all standards-based telephony equipment using relatively inexpensive hardware.