1)   TERAVoice Server 2004
TERAVoice is a high-performance telephony platform for Windows that can implement any type of telephony application like voicemail, automated attendants, voice menus, waiting queues for call centers, H.323 to PSTN gateway and custom IVR applications.
teravoice, voice, mail, voicemail, ivr, h.323, h323;voip, bridge, gateway, gatekeeper,

 2)   Dynasoft TeleFactura 3.90
Web-ready, Dynasoft TeleFactura is the definitive voice/data billing and engine solution for telecom service providers, callshop minute resellers, and office service operators distributing telecom and data services.
telecom, telephony, VoIP, Voice over IP, least cost routing, CDR, call data records, Radius, AAA, YATE,

 3)   GNU Gatekeeper 2.2.6
A free H.323 gatekeeper to build VoIP networks, route calls and do authentication and accounting.
h.323, h323, voip, gatekeeper, call routing, billing, accounting,