Built-in SIP Proxy server, Allow up to 100 registration users
IAX2
Automated Attendant (AA)
Interactive Voice Response (IVR)
Voicemail (VM)
Call Detail Records (CDR)
Support G.723.1(6.3k/5.3k), G.729A/B, G.711(A-law/U-law),
G.726 voice codec
Backup system configuration through Web and USB flash disk
Built-in NAT and firewall functions
One Touch Dialing with ET747K
Build-in 3 FXO/CO-lines (expandable to 7 FXO/CO-lines), 1 FXS
for life line or FAX