SIP 2.0 (RFC3261) and correlative RFCs..
Full duplex hands-free speaker phone.
NAT transverse：support STUN client.
SIP support SIP domain, SIP authentication (none, basic, MD5), DNS name of server,
Peer to Peer/ IP call.
SIP support 2 SIP lines or only one IAX2 lines. Can connect to SIP1 and SIP2 server at the same time DTMF：Support SIP info, DTMF Relay, RFC2833.
SIP application: support Call forward/ transfer/holding/ waiting / 3 way talking/ paging
and intercom/pickup/join call/click to dial/call park.
Call control features: Flexible dial map, Hot line,empty calling reject, Black list for reject
authenticated call, limit call, No disturb, Caller ID.
Support Phonebook 500 records
Incoming calls / Outgoing calls / Missing calls. Each support 100 records
Support conference and voice record on SIP server
10 kind of ring type
Support SRTP
Support MWI
 

Voice
Codec: G.711 A/U Law, G.722, G.723, G.729,
Echo cancellation: Support G.168, and Hands-free can support 96ms, Hand free Speaker Phone.
Support Voice Gain Setting, VAD, CNG
 

Networking
WAN/LAN: Support Bridge and Router model
Support basic NAT and NAPT
Support PPPoE for xDSL
Support DHCP Client on WAN
Support VLAN (optional: voice vlan/data vlan)
QoS with DiffServ
Support DMZ
Support main DNS and secondary DNS server
Support DNS Relay, SNTP Client, Firewall
Network tools in telnet server: Including ping, trace route,
telnet client
 

Protocols
MAC Address
TCP:Transmission Control Protocol
DHCP:Dynamic Host Configuration Protocol
PPPoE:PPP Protocol over Ethernet
SNTP, Simple Network Time Protocol
STUN - Simple Traversal of User Datagram ...
MD5 Message-Digest Algorithm
DNS: Domain Name Server
RTP: Real-time Transport Protocol
RTCP:Real-time Control Protocol
Telnet:Internet's remote login protocol
HTTP:Hyper Text Transfer protocol
FTP:File Transfer protocol
TFTP:Trivial File Transfer Protocol
 

Maintenance and Management
Web ,telnet and keypad management
Management with different account right
Upgrade firmware through POST mode
Upgrade firmware through HTTP, FTP or TFTP.
Telnet remote management/Upload/download setting file
Safe mode provide reliability
Supoort Auto Provisioning (upgrade firmware or
configuration file)
Support S og