Basic Feature
Support SIP 2.0 (RFC3261) and correlative RFCs
Support IAX2 (Optional)
Support PSTN call(Optional)
SIP supports 4 SIP servers, and backup SIP servers. Can connect to these SIP servers at the same time.
Voice Codec: G. 711A/u, G. 7231 high/low, G. 729A/b, G. 722, G. 726, iLBC, AMR-NB, AMR-WB
Video Codec: H. 263, H. 264, MPEG4
Video solution: QCIF, CIF, QVGA
Image format: PEG, PNG, GIF and BMP
Video format: MP4, 3GP and flv
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
Support jitter buffer
Full duplex hands-free speakerphone
SIP support SIP domain, SIP authentication (none, basic, MD5), DNS name of server, Peer to Peer/ IP call
DTMF Relay: Support inband, SIP info, RFC2833
Support customized music rings
Support STUN
Support SMS based on SIP
Volume(handfree/handset/headset/ring) adjustment
Professional Speaker/handset HD Voice
Ergonomic handset(acoustical cochlea)

Advanced Application

Features
Touched, Large DOT matrix LCD display and softkeys make user easier to use
Friendly graphic menu
Multilanguage realizes localization
SIP application: Support forward/transfer (blind/attended/alert)/ holding/ waiting/ 3 ways conference/ paging and intercom/ call park/ pickup/ join call/ redial and unredial/ click to dial//secondary dialing automatically
Predial
Voice recording during talking /local
Call control features: Flexible dial map, hotline, empty calling no. Reject service, black list for reject authenticated call, white list, limit call, do no disturb, auto answer, caller ID, CLIR (reject the anonymous call), CLIP (make a call with anonymous), Dial without register
Human voice caller ID indication
Human voice num keypad indication
Voice recording during talking/auto answer/local
Incoming calls /outgoing calls / missing calls. Each support100 records.
Support Phonebook 2000 records
Phone book records export/import
XML phone book
Photo frame
Media player(MP4, MP3, wav, WMA)
USB disk file management
System files management
Support VoIP(SIP/RTP) encryption (e. G. RC4)