WILDIX is a FREE IAX  Softphone it's windows based and support:
* All Wildix USB phones ( K1000, Perfectone UP-90, BeyondTel SX-06 )
* All Asterisk PBX
* IAX2 protocol

Features:

* Easy user interface
* Minimum system requirements with maximum standard softphone features
* Blind Transfer and Assisted Transfer are completely supported
* Hold and Flash button
* Supports Up to 6 lines
* Supports CallerID
* Gives superb voice quality on all version of Windows

* Easy to install and configure
* Speed dialing
* NAT/Firewall support
* Full integration of USB handset and headset devices
* Works with any full-duplex sound card
* Missed and Dialed Calls

Call Control Capabilities

* Speakerphone capabilities with a real-time host based acoustic echo canceller
* Volume control
* Selection of the audio device used by the softPhone (audio cards must be full-duplex)
* Fast connect procedure
* Voice jitter buffer
* Real time audio streaming
* Supports VAD (Voice Activity Detection)
* Speech codecs supported: G.711 (a-law, u-law), GSM, iLBC, Speex
* Support DTMF
* Address book

Download now!