The Grandstream UCM6308 IP PBX is a high-capacity unified communication system featuring 8 FXO and 8 FXS ports, triple Gigabit Ethernet with PoE+, and support for up to 3000 users and 450 concurrent calls. With built-in conferencing, cloud management via GDMS, and no licensing fees, it is ideal for medium to large businesses requiring scalable VoIP and PSTN integration.