Using standard Personal Computer (PC) hardware along with OpenVox A400E PCI Express cards allows home users and business customers alike to build inexpensive Internet Protocol Private Branch Exchange (IP PBX) platforms. The A400E is a half-length, 4-port Peripheral Component Interconnect (PCI) Express card. The A400E 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 A400E is officially certified for use with Trixbox®.