UCM6304

Here’s a thorough overview of the Grandstream UCM6304 IP PBX:

    Capacity & Core Performance

• Scalable user base: Supports up to 2,000 users and 300 concurrent calls (or up to 450 per some listings) 

• Conferencing:

  • Audio bridge: up to 200 participants

  • Video conferencing: up to 4 rooms or 40 participants 

    Interfaces & Hardware

• Analog ports:

  • 4 FXO ports to connect PSTN lines

  • 4 FXS ports for analog phones or fax (lifeline capability) 

• Network:

  • 3× Gigabit RJ45 ports with PoE+; can be configured in switch, router, or dual mode, and includes NAT firewall traversal 

• Connectivity extras:

  • 2× USB-A 3.0 ports

  • 1× SD card slot for local recording/storage 

• Front display:

  • 320×240 color touch LCD with soft keys for quick navigation 

   Unified Communications & VoIP Features

• Zero‑configuration provisioning for Grandstream endpoints

• Includes built-in:

  • Audio/video conferencing

  • Instant messaging

  • Auto-attendants, IVR, call queues, caller ID, CDR, fax-to-email

• Supports Wave soft-phone app (desktop & mobile)

• Compatible with full range of codecs: Opus, G.711, G.722, G.729, T.38 fax, etc. 

    Security & Network Features

• Secure boot, unique device certificate, random default passwords, support for SRTP/TLS/HTTPS 

• Integrated NAT router capable of router/switch/NAT modes and firewall traversal 

• Compatible with GDMS for remote cloud-based provisioning & monitoring 

   Target Audience & Use Cases

• Ideal for medium-sized businesses requiring robust on-prem IP PBX with hybrid analog and VoIP.

• Great when analog line redundancy is needed (FXO/FXS) alongside modern SIP and video.

• Suitable for multi-site or multi-department setups benefiting from call queues, conferencing, and unified communication features.