... .168, and Hands-free can support 96ms, Hand free Speaker Phone Support Voice Gain Setting, VAD, CNG DTMF:Support SIP info ... SIP domain, SIP authentication (none, basic, MD5), Peer to Peer/ IP call Call control features: Flexible dial map, Hotline, Empty callingn ... Auto Provisioning (upgrade firmware or configuration file) Support Syslog voip phone sip phone ACOM IP phone