S100 - is a PBX of VoIP technology. It has all the functionality that a telephone exchange can have.

IP phones: 100 (expandable up to 200)
Simultaneous conversations: 30 (expandable up to 60)
Number of trunks: 100
Analog Ports (FXS/FXO/BRI): 16
Wireless channels (GSM/3G/4G): 6
Digital ports (E1/T1/PRI): 2