Telephony Features:
- Caller ID detection
- Call transfer (attended and blind), call waiting
- Call forwarding, 3-way conferencing
- Busy-tone disconnect, polarity reversal
- Hotline, speed dial, do not disturb
- Flexible dial plans and number manipulation
Security and Networking:
- Built-in firewall
- IP blacklisting and access control
- NAT traversal (STUN)
- TLS and SRTP encryption
- DHCP, PPPoE, static IP
- VLAN tagging (802.1Q)
- OpenVPN support




