The S100 by Yeastar is the popular choice by users because it offers great performance with the option to expand from 100 extensions and 30 concurrent calls to up to 200 extensions with 60 concurrent calls. Offered as a pure IP telephony device, the S100 contains the capacity to upscale to up to 2 Primary Rate ISDN ports or up to 16 analogue trunks, extensions, BRI ports or up to 6 3G trunks, all without needing to upgrade the existing hardware.
