VoIP equipment Grandstream UCM6301 IP PBX

Quick overview from the supplier:

Grandstream UCM6301 IP PBX, 500 Users, 75 concurrent calls, 1хFXS, 1xFXO, 1xWAN, 1xLAN // Supports up to 3000 users and up to 450 concurrent calls Zero configuration provisioning of Grandstream SIP endpoints Built-in conferencing & meetings platform; supports desktop, Wave app, and SIP endpoints Wave for Android, iOS, Chrome and Firefox browsers allows communication with all UCM6300 users & solutions API available for third-party integrations, including CRM and PMS platforms Advanced security protection with secure boot, unique certificate and random default password to protect calls and accounts Three Gigabit auto-sensing RJ45 network ports with integrated PoE+ and support NAT router Automated NAT firewall traversal service facilitates secure remote connections Supports Full-Band Opus voice codec and H.264/H.263/ H.263+/H.265/VP8 video codec, jitter resilience up to 50% packet loss Compatible with GDMS for cloud setup, management and monitoring Based on Asterisk* version 16 open source telephony operating system