voip pbxs,ip pbxs,voip adapter,China voip provider Houyuan Technology (HK) Limited ( houyuanhk.com ) is a professional voip pbx manufacturer in China. 1.Open Source Asterisk 2.uClinux Operation System 3.Configurable IVR menu 4.Over 50-100 available SIP/IAX2 extensions for SMB use 5.20 concurrent calls 6.Voicemail to Email 7.Call Forward , Call Waiting, Call Transfer (Blind Transfer/ Attender ...