The Grandstream UCM6308 IP PBX is an enterprise-grade, on-premise unified communications platform designed to support up to 3,000 users and 450 concurrent .Key SpecificationsCapacity: Supports up to 3,000 users and 450 concurrent VoIP calls.Ports: Equipped with 8 FXS analog telephone ports and 8 FXO PSTN trunk ports.Network: Three self-adaptive Gigabit network ports with integrated PoE+ and NAT router support.Conferencing: Supports up to 40 video conference participants and 160 voice conference participants.Peripherals: Includes USB 2.0, USB 3.0, an SD card interface, and a 320x240 color touch LCD screen. This FeaturesNo Licensing Fees: Operates with zero monthly subscription or per-user fees.Remote Access: Features an automated NAT firewall traversal service for secure remote connections