#1: IPv6, IPv4#2: Call waiting#3: SIP/IMS#4: Call Transfer (Blind transfer, Attend transfer)#5: SIP v2.0 (RFC3261) based on UDP/TCP/TLS#6: Call Forwarding (Unconditional, No reply)#7: Fax over T.38 and Pass-through#8: Speed Dial#9: QoS:L3 DIFFServ, 802, 1P/Q VLAN Tagging#10: Do Not Disturb(DND)#11: 3-way conference#12: Automatic firmware upgrade and configuration via HTTP/HTTPS#13: Hunting group#14: System logs & CDR#15: Voice Mail#16: Flexible routing & dial plan#17: Pluse Dialing#18: Backup and restore#19: MWI#20: SNMP/TR-069#21: 5 km long haul#22: TLS/SRTP#23: Music on hold