ZOIPER Free Version 2.0 is a new generation SIP and IAX softphone compatible with the Asterisk platform as any other SIP or IAX capable system. ZOIPER Free Edition features include: SIP + IAX/IAX 2 protocols, STUN support, STUN server per account, Echo cancellation, DTMF tones sending, Support for multiple audio devices, Automatic user registration, Call transfer, Hold function, Codecs: GSM, ulaw, alaw, speex, ilbc, Adaptive, Call history,...