... can support 96ms, Hand free Speaker Phone Support Voice Gain Setting, VAD, CNG DTMF:Support SIP info, DTMF Relay, RFC2833 Full duplex ... call/click to dial/call park SIP support SIP domain, SIP authentication (none, basic, MD5), Peer to Peer/ IP call Call control features: Flexible ... Support Auto Provisioning (upgrade firmware or configuration file) Support Syslog voip phone sip phone ACOM IP phone