SIP Clients

Program	Operating systems	License	Protocols	Codecs	Encryption	Other capabilities
Jitsi	Linux, Mac OS, Windows (all java supported)	LGPL	SIP/SIMPLE, XMPP/JingleSTUN ICE, TURN	SILK, G.722, Speex,Opus, G.711 (PCMU/PCMA), iLBC,GSM, G.729, H.264,H.263, VP8	ZRTP, SRTP, TLS	Text messaging, audio/video telephony, IPv6 (often broken,[9] P2P not supported[10]), call recording, 64-bit
Linphone	Linux, Windows, Mac OS, Android, iPhone, BlackBerry	GPL	SIP	Speex, G711, GSM,G.722; VP8 (WebM),H263, MPEG4, Theoraand H264 (plugin)	TLS, SRTP, ZRTP	Video, IM, STUN, IPv6 (disables IPv4 support when enabled, P2P supported only by version 3.5.1-2)
MicroSIP	Windows	GPL	SIP, STUN,ICE, SIMPLE	Speex, iLBC, GSM,G.711, G.722, G.729,SILK, Linear PCM	TLS, SRTP	Video, voice, IM and Presence
PhonerLite	Windows	Free	SIP	Unknown	TLS, SRTP, ZRTP	Conferencing, call redirection, call recording
QuteCom	Linux, Mac OS X,Windows XP/2000	GPL	SIP	G.711, G.729, iLBC,AMR-NB, G.722, Speex,AMR-WB (G.722.2),H.263, H.263+, H.264,Dirac[13]	SRTP	Video, IM (MSN, AIM, ICQ, Yahoo!, XMPP, Google Talk), voicemail, wengo to phone, conferencing.
Yate Client	Linux, Mac OS, Windows	GPL	SIP, IAX,XMPP, H.323	G.711a, G.711u, GSM 06.10, iLBC, Speex,G.723, G.726, G.728,G.729	Unknown

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