... call transfer, call pick-up, 3-way conference, caller ID, CRBT, T.38 Fax relay, flexible call routing with ... SNMPv2, Telnet, TFTP, SyslogAuxiliary MaintenanceInquiry and set by phone dialer, factory reset buttonProtocol and standardProtocol SIP (RFC3261 and ... secondary SIP account, register by DNS, DNS SRVStandard Caller ID detection(FSK/DTMF), configurable call progress tone planHardware LEDStatus ...