ZOIPER Free IAX and SIP softphone

ZOIPER 2.0 Free IAX and SIP is a user-friendly softphone, compatible with Asterisk or any other IAX or SIP capable system. High-quality VoIP calling experience with features like: IAX + SIP protocols, SIP over TCP/TLS/UDP(STUN support), Echo cancellation, DTMF tones, Multiple audio devices support, Automatic user registration, Call transfer, Hold function, Multilanguage support, Portable storage compatibility, Codecs: GSM, ulaw, alaw, speex, ilbc