1)   4PSA VoipNow Professional 1.5
4PSA VoipNow is the leading Linux IP PBX server software designed for providing hosted PBX services and enterprise VoIP. Advanced features like IVR, call queue, callback, calling card and conference are available.
voip, voip server, pbx, IP PBX, softswitch, voip pbx, pbx software, asterisk pbx, asterisknow, trixbox,