HD voice: HD handset, HD speaker
Hearing aid compatible (HAC) handset
Codecs: AMR-WB (optional), AMR-NB (optional), Opus*, G.722, G.711(A/µ), G.723.1, G.729AB,G.726, ILBC
DTMF: In-band, Out-of-band (RFC 2833) and SIP INFO
Full-duplex hands-free speakerphone with AEC, VAD, CNG, AEC, PLC, AJB, AGC
16 VoIP accounts
Call hold, mute, DND
One-touch speed dial, hotline
Call forward, call waiting, call transfer
Group listening, SMS, emergency call
Redial, call return, auto-answer
3-way conferencing
Direct IP call without SIP proxy
Ring tone selection/import/delete
Set date time manually or automatically
Dial plan, XML Browser, Action URL/URI
RTCP-XR (RFC3611), VQ-RTCPXR (RFC6035)
A USB port (2.0 compliant) for Bluetooth earphone through BT40, Contact synchronization
through BT40, Wi-Fi through WF40, USB call recording through USB flash drive
Enhanced DSS key
SIP v1 (RFC2543), v2 (RFC3261)
Call server redundancy supported
NAT traversal: STUN mode
Proxy mode and peer-to-peer SIP link mode
IP assignment: static/DHCP/PPPoE
HTTP/HTTPS webserver
Time and date synchronization using SNTP
UDP/TCP/DNS-SRV(RFC 3263)
QoS: 802.1p/Q tagging (VLAN), Layer 3 ToS DSCP
SRTP for voice
Transport Layer Security (TLS)
HTTPS certificate manager
AES encryption for the configuration file
Digest authentication
OpenVPN, IEEE802.1X
IPv6, LLDP/CDP/DHCP VLAN, ICE
