Yeastar S412 8 Users 8 Concurrent Calls Modular IP-PBX with auto-provisioning capabilities for major VoIP brands, including Polycom, Cisco, Grandstream, Snom, and Yealink. S412 supports up to 8 SIP accounts, 4 SIP trunks, 12 analog lines, 4 digital lines, or 2 cellular lines. It comes pre-configured