Cactus

Cactus is a software-based public branch exchange (PBX) for Voice over IP telephones. It runs on any Windows PC with a network adapter and also implements a VoIP-ISDN gateway if an optional ISDN card is plugged into the PC. Cactus is SIP compliant and avoids external IP traffic for internal telephone conversation. For external calls, all SIP-based providers like SipGate can be used.
Price USD 110.84
License Free to try
File Size 1.22 MB
Version 1.33
Operating System Windows 95, Windows 2000, Windows Vista, Windows 98, Windows Me, Windows, Windows NT, Windows 7, Windows XP
System Requirements None