Using standard Personal Computer (PC) hardware along with OpenVox A400P PCI cards allows home users and business customers alike to build inexpensive Internet Protocol Private Branch Exchange (IP PBX) platforms. The A400P is a half-length, 4-port Peripheral Component Interconnect (PCI) card and is fully compatible with Digium® TDM400P/TDM410P cards and modules. The A400P is compatible with leading open source IP PBX software such as Asterisk®, Trixbox®, and Elastix® (OpenVox are an Elastix® Strategic partner), which support all the sophisticated features of expensive high-end PBX/Voicemail platforms. OpenVox are a Fonality® Authorized / Certified Ecosystem (FACE) partner and the OpenVox A400P is officially certified for use with Trixbox®.