Yeastar hybrid PBX S20, VoIP SIP protocols, up to 20 users, max 10 concurrent calls,  up to 4 FXS/FXO/BRI ports, up to 1 x GSM port.   Up to 20 SIP trunks, 2 Slots for Voice Modules.  Call Recording, IVR, Conference, VoiceMail, Queues, Provisioning for IP phones.

S20 is a stand-alone telephone system offering an unrivalled range of features to small business with less than 20 users. It supports 10 concurrent calls and various combinations of telephony ports including FXS, PSTN, ISDN BRI, and GSM/CDMA/3G.

• 20 Users

• 10 Concurrent Calls

• Up to 4 FXS/FXO Ports

• Up to 4 BRI Ports

• Up to 1 GSM/CDMA/3G Channel