Zoiper Free IAX and SIP softphone

ZOIPER 2.0 Free SIP and IAX is a user-friendly softphone, compatible with Asterisk or any other SIP or IAX capable system. Great VoIP calling experience with features like:

SIP + IAX / IAX 2 protocols
Available codecs – GSM, ulaw, alaw, speex, ilbc
STUN support
STUN server per account
Two accounts
DTMF tones sending
Echo cancellation
Codec settings per account
Account password encryption
Call history
Hold function
Quick dial panel
Optional Automatic pop-up window for incoming call
Call logs
Minimize on tray
Minimize on start up
Always on top
Adaptive Jitter Buffer
Support for multiple audio devices
Address book
Quickdial pad
Automatic user registration
Call transfer
Voice mail message information
Portable ZoIPer with portable devices (like USB, flashcards, etc.)
Multilanguage support