asterisk180 Beta release

Asterisk is a complete PBX in software. It provides all of the features
you would expect from a PBX and more. Asterisk does voice over IP in
three protocols and can interoperate with almost all standards-based
telephony equipment using relatively inexpensive hardware.

Asterisk provides voicemail services with directory, call conferencing,
interactive voice response, and call queuing. It has support for
three-way calling, caller ID services, ADSI, SIP, and H.323 (as both
client and gateway)