Grandstream UCM6308 IP PBX for 3,000 Users

The Grandstream UCM6308 leads this group with capacity for 3,000 users and 450 concurrent G.711 calls or 300 concurrent SRTP calls. Eight FXS RJ11 and eight FXO RJ11 ports make it suitable for a large facility requiring many analog device and line connections beside SIP. Three self-adaptive Gigabit ports connect it to the network with PoE+ and a NAT router. Two included 12V power adapters provide failover at the adapter level. The appliance supports rack or desktop placement, and a 128×32 dot-matrix LCD presents local status to technicians.

Managing Grandstream UCM6308 Capacity

Communications teams need two separate calculations: the 3,000-user account base and an operating ceiling of 450 concurrent G.711 or 300 concurrent SRTP calls. The distinction is useful at headquarters where departmental traffic varies or encrypted calling is widely used. Eight FXO ports accept eight analog lines, while eight FXS ports serve eight analog devices. Two USB 3.0 ports and one SD interface add local connections that should remain physically accessible.

Role in Large Saudi Facilities

The UCM6308 fits headquarters, service centers, universities, hospitals, and multi-building organizations managing a large user estate while retaining dense analog connectivity. Rack mounting integrates the appliance with communications-room network equipment, and desktop placement remains available where no rack is used. Three network ports support the physical topology chosen by the network team, while the local display gives technicians an immediate reference during inspection.

UCM6308 Compared with UCM6304

The UCM6308 supports 3,000 users, 450 concurrent G.711 calls, and 300 concurrent SRTP calls, with eight FXS and eight FXO ports. The named UCM6304 supports 2,000 users, 300 concurrent G.711 calls, and 200 concurrent SRTP calls, with four FXS and four FXO ports. Both have three Gigabit interfaces, rack or desktop placement, and two included 12V adapters for failover. The UCM6308 is therefore aimed at the site requiring the higher capacity and more analog connections.

Connection Execution

The package includes the UCM6308, Ethernet cable, two 12V power adapters, and quick installation guide. Prepare routes for eight FXO lines, eight FXS devices, and three Gigabit connections before placing the unit in a rack. Connect both power sources according to the failover plan and preserve access to the display, USB ports, and SD interface. Group and identify RJ11 cables so every line and device can be traced during service.

Package Contents

• UCM6308
• Ethernet cable
• 12V power adapter × 2
• Quick Installation Guide