Caller ID, Call Transfer, Call History, Call Hold, Do No Disturb, Call Forwarding, Call Park, Call Pickup, Ring Group, Business Calling Features, Video Calls, VPN Client (PPTP/L 2TP), VPN server (PPTP/L 2TP)
IAX2 (RFC 5456), SIP (RFC 3261)
TLS, STRP, UDP, TCP
Audio Codecs: Opus/G.722/G.711-Ulaw/G.711-Alaw/G.726/G.729/GSM/SPEEX
Video Codecs: VP8/H.261/H.263/H.263+/H.264
Fax: T.38 (passthrough)