| call forwarding | call transfer | call park | receiving call |
| Original ringtone | special waiting music | Multi-level IVR | Intercom and call system |
| Barge | conferences | video call | DID |
| call queue | Follow me | ring group | Recording |
| billing | Telephone directory | voicemail | failed2ban |
| Redirect voicemail to email | attendant console | Flexible orientation | T.30/T.38 Fax |
Defense Against Attack: Fail2Ban, White List, Black List, ACL, etc.
TLS, SRTP, ZRTP encryption
Data protection with multi-level user permissions
Built-in IP firewall to prevent malicious attacks.