Basic Features
Support SIP 2.0 (RFC3261) and correlative RFCs
Support IAX2
SIP supports 3 SIP servers. Can connect to 3 SIP servers at the same time.
Codec:G.711A/u, G.723, G.729a/b, G.722
Echo cancellation: G.168 Compliance in LEC, additional acoustic echo cancellation(AEC) can reach 96ms max filter length in hands-free mode
Support Voice Gain Setting, VAD, CNG
Full duplex hands-free speakerphone
SIP support SIP domain, SIP authentication (none, basic, MD5), DNS name of server, Peer to Peer
DTMF MODE:support DTMF_RELAY, SIP_INFO, RFC_2833

Advanced Application Features
Large dot matrix LCD display and softkeys make user easier to use
2 headset interface ( 3.5mm Jack or RJ9 connector)
6 memory keys
Support PoE (optional -BW535P)
Multilanguage realizes localization
SIP application: support call forward/ transfer/ holding/ waiting/conference/
Call control features: flexible dial map, hotline, empty calling no. reject service, black list for reject authenticated call, limit call, no disturb, caller ID
Incoming calls /outgoing calls / missing calls each support 100 records
Support Phone Book 500 records
Support conference and voice record on SIP server
Support SMS

Network Features
WAN/LAN: 10/100M Ethernet ports, supports Route and Switch mode.
Support PPPoE for xDSL
Support basic NAT and NAPT
NAT transverse:support STUN client
Support DHCP client on WAN
Support DHCP server on LAN
Support main DNS and secondary DNS server.
Support VLAN
Support DMZ
Support DNS Relay, SNTP Client, Firewall
Support VPN (L2TP)
QoS with DiffServ
Network tools in telnet server: including ping, trace route, telnet client

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