Kerio Operator Softphone is a software-based phone client that lets you make and receive calls on your Android mobile device from your office phone system. Kerio Operator Softphone is designed to work with Kerio Operator IP PBX or any other SIP based VoIP service.

NOTE: Kerio Operator Softphone supports auto-provisioning (auto-configuration) with Kerio Operator SIP server but can be configured manually to operate with any SIP based VoIP server. Auto-provisioning requires a trusted and valid server SSL certificate issued by trusted Certification Authority to be installed on Kerio Operator server. Self-signed SSL certificates cannot be used.

Main features
* Excellent voice quality
* High security with call encryption support
* Multitasking support for operation in background
* Multiple languages support - English German French Spanish Russian Chinese (Simplified and Traditional) Japanese Korean

Telephony features
* Support for up to 4 accounts on any SIP-compliant server (Automatic provisioning with Kerio Operator)
* Integrate contacts from your phone's native contacts directory
* Call display and voice-mail indicator
* Transfer to speakerphone mute and hold functionality
* Call history
* Ringtones and contact avatars
* Dial plan support
* Multiple call support - swap between two active calls merge and split calls transfer calls
* DTMF via RFC 2833 SIP INFO and in-band
* VPN support
* Automatic codec selection for best call quality
* Supported codecs: G.711 a/u G.722 (HD) iLBC GSM OPUS

Advanced features
* Global IP support
* IPv6 support
* STUN & ICE support
* Noise reduction echo cancellation and VAD (Voice Activation Detection)
* Quality of Service
* Security and call encryption via TLS and SRTP
* DNS SRV record look-up
* Call quality statistics

Supported accessories
* Headset with microphone - wired or Bluetooth
* Headphones (without microphone) - device's built-in microphone is used

Please note that using Kerio Operator Softphone as a default dialer may interfere with dialing 911 emergency services (112 emergency services in Europe).