Yeastar S20 Stand-alone IPBX systemYeastar S20 Stand alone IPBX system Yeastar S20 is a stand alone PBX system with unrivalled range of features for business with less than 20 users. Its built to be simple to use and powerful in production. 20 Users 10 Concurrent Calls Up to 4 FXS FXO BRI Ports Up to 1 GSM 3G 4G Channel 20 VoIP Trunks Support Call Recording and IVR Key Features: Modular Design for Flexible Connectivity: Customize your telephony interfaces with two onboard module slots,