This is a comparison of voice over IP (VoIP) software used to conduct telephone-like voice conversations across Internet Protocol (IP) based networks. For residential markets, voice over IP phone service is often cheaper than traditional public switched telephone network (PSTN) service and can remove geographic restrictions to telephone numbers, e.g., have a PSTN phone number in a New York area code ring in Tokyo.
For businesses, VoIP obviates separate voice and data pipelines, channelling both types of traffic through the IP network while giving the telephony user a range of advanced abilities.
Softphones are client devices for making and receiving voice and video calls over the IP network with the standard functions of most original telephones and usually allow integration with VoIP phones and USB phones instead of using a computer's microphone and speakers (or headset). Most softphone clients run on the open Session Initiation Protocol (SIP) supporting various codecs. Skype runs on a closed proprietary networking protocol but additional business telephone system (PBX) software can allow a SIP based telephone system to connect to the Skype network. Online chat programs now also incorporate voice and video communications.
Other VoIP software applications include conferencing servers, intercom systems, virtual foreign exchange services (FXOs) and adapted telephony software which concurrently support VoIP and public switched telephone network (PSTN) like Interactive Voice Response (IVR) systems, dial in dictation, on hold and call recording servers.
Some entries below are Web-based VoIP; most are standalone applications.
|Program||Operating systems||License||Costs||Protocols||Codecs||Encryption||Max conference peers||Other abilities||Latest release|
|AudioCodes MobilityPLUS||Windows, Android, iOS||Proprietary||?||SIP, RTP, XMPP, STUN, ICE||G.722 wideband, G.711a, G.711u, iLBC, G.729a, SILK, GSM, VP8, H.264, Opus||TLS, SRTP||Unknown||Voice, video, IM, Group chat, content sharing, SMS and MMS over IP services, native and social network contacts integration, incoming call/IM push notifications.||2014|
|Avaya Application Server 5300 Soft Client||Windows||Proprietary||?||SIP, RTP||Unknown||TLS, SRTP||Unknown||2.0; 2010|
|Blink||Linux, macOS, Windows||Mixed: free software versions under GNU GPLv3 + shareware versions under gplv3 with exception of including proprietary code||macOS version proprietary on App Store, free version limited to sponsored SIP provider; Windows version proprietary; Linux version open source||ICE, SIP, MSRP, RFB (VNC), XCAP||Opus, speex, G.722, GSM, iLBC, PCMU, PCMA||TLS, SRTP and ZRTP on all versions, OTR/SMP on Linux and macOS only||No limit||IM, file transfer, desktop sharing, multi-party conference, wideband||Blink Qt|
|CSipSimple||Android||GPL||Free||SIP, ICE, STUN, TURN||Opus, AMR, G.711 (u-law/a-law), speex, G.722, GSM, iLBC, G.729 (need to buy a licensed plugin), iSAC, SILK (narrow-band/wide-band/ultra wide-band)||SRTP, SIP over TLS 1.0 and ZRTP||Unknown||SIP SIMPLE messaging, Support for IPv6, Integration with Android operating system with filters and rewriting rules||1.0.2; November 2014|
|Cisco IP Communicator||Windows||Proprietary||Free (for Cisco SMB Partners only)||SCCP (Skinny), SIP, TFTP, HTTP (for XML Services)||G.722 wideband, G.711a, G.711u, iLBC, iSAC, G.729a, G.729ab||SRTP||Unlimited (with bridge), 2 otherwise||Call Recording, Silent Monitoring, Multiple lines and directory numbers, Configurable speed dial, Calling name and number display, Call Waiting, Call Forward, Call Transfer, Three-Way Calling (conference), Call Park, Call Pickup, Redial, Hold, Barge, Callback, Extension Mobility, Message waiting indicator, iDivert, Meet Me conferencing, Group Pickup, Do Not Disturb, XML Services||8.6.6; April 27, 2016|
|CounterPath Corporation Bria||Windows, macOS, iOS, Android||Proprietary||SIP, RTP, XMPP, STUN, ICE||G.722 wideband, G.711a, G.711u, iLBC, G.729a, SILK, GSM, VP8, H.264, Opus||TLS, SRTP||6 party voice, 3 party video||Voice and video calling, SIP and XMPP messaging support, group chat, file, image and document sharing, contact integration, incoming call/IM push notifications||5.3.4 July 23, 2018|
|Discord||macOS, Android, iOS, Windows, Linux||Proprietary||Free, Premium "Nitro" Subscription for Additional Features.||?||Opus||TLS||5,000 soft limit||IM, file sharing, in-game overlay||02.01.2018; February 1, 2018|
|Ekiga||Linux, Windows, OpenSolaris||GPL||Free||SIP, H.323, STUN, Zeroconf, XMPP, RTP||H.263, H.264/MPEG-4 AVC, Theora, iLBC, Speex, SILK, GSM, ...||No||Unknown||Video, IM, LDAP, Call Forwarding, Call Transfer, Auto-answering, PC to phone, phone to PC, Multiple accounts, USP support, Message waiting indicator, SIMPLE-based presence etc.||4.0.1 (February 21, 2013[±])|
|Empathy||Linux||GPL||Free||SIP, XMPP (Jingle), ICE (STUN-TURN), Zeroconf||Unknown||No||Unknown||IM, multi-user A/V, collaborative applications||3.12.12 (May 13, 2016 ) [±]|
|Eyeball Chat||Windows||Proprietary||Free||SIP, STUN, ICE, XMPP||Unknown||Yes||5||IM, Conferencing, Voice, Video and SIMPLE based presence||Windows 3.2; 2009|
|eyeBeam||Windows||Proprietary||?||SIP-SIMPLE||Unknown||TLS, SRTP||6 party audio; 3 party video||Voice and Video calling; IM; Import Microsoft Outlook Contacts; USB Support; Call Recording and Conferencing||22.214.171.124; March 2010|
|Google+ Hangouts||Linux, Windows, macOS, Android, iOS||Proprietary (using libjingle)||Free||XMPP||H.264/SVC, H.264/AVC, H.263 and VP8||SRTP||10||Video, chat, screen sharing, with additional tools available as "Hangout Apps".||Google Chrome Web Store extension |
2013.626.1614.1 (July 9, 2013 ) [±] 
|IBM Sametime||Linux, macOS, Windows, mobile||Proprietary||?||SIP-SIMPLE, T.120||H.323||TLS||Unknown||IM, File transfer, Voice, Presence, Server stored contact list, HTTP tunneling, plugins, embedable in Lotus Notes||8.5.2; May 8, 2011|
|iCall||Linux, macOS, Windows, iOS, Android||Proprietary||Free||SIP, AIM, ICQ, XMPP||Speex, CELT, WebM||TLS, ZRTP||No limit||Video, file transfer, PC to phone, phone to PC, IM (MSN, AIM, ICQ, Yahoo!, XMPP, Google Talk), Voicemail||7.1.522|
|Jitsi||Linux, macOS, Windows (all java supported). Experimental Android builds are also available.||Apache||Free||SIP-SIMPLE, XMPP-Jingle STUN ICE, TURN||SILK, G.722, Speex, Opus, G.711 (PCMU/PCMA), iLBC, GSM, G.729, H.264, H.263, VP8||ZRTP, SRTP, OTR, TLS||Unknown||Text messaging, audio-video telephony, IPv6 (often broken, P2P not supported), call recording, 64-bit||2.10 (build.5550) (February 5, 2017[±])|
|KPhone||Linux (KDE)||GPL||Free||SIP, STUN, NAPTR-SRV||Unknown||SRTP||Unknown||Video, voice, IM, external Sessions, IPv6 support for UDP||1.2 (November 2008)|
|Librestream Onsight Connect||Windows, Android, iOS||Proprietary||?||SIP, RTP, STUN||G.711, H.264, MPEG, and others||TLS, SRTP||Unknown||Voice, video, conferencing, image sharing, incoming call/IM push notifications.||February 27, 2018|
|Linphone||Linux, Windows, macOS, Android, iPhone, BlackBerry||GPL||Free||SIP||Speex, Opus, G711, GSM, G.722, VP8 (WebM), H263, MPEG4, Theora and H264 (plugin)||TLS, SRTP, ZRTP||Unknown||Video, IM, STUN, IPv6 (disables IPv4 support when enabled, P2P supported only by version 3.5.1-2)||3.11.1; March 10, 2017|
|Messages||macOS||Proprietary||Free, only MacOS and iOS||SIP AIM ICQ XMPP||H263, H264||Unknown||Unknown||Integrated, PBX independent||7.0; July 25, 2012|
|MicroSIP||Windows||GPL||Free||SIP, STUN, ICE, SIMPLE||Speex, iLBC, GSM, G.711, G.722, G.729, SILK, Linear PCM||TLS, SRTP||Unknown||Video, voice, IM and Presence||3.18.3 March 2018|
|Mirial Softphone (Mirial s.u.r.l.)||Windows 2000-XP-2003-Vista-7 (including 64-bit versions), macOS (x86)||Proprietary||not free||SIP, RTSP||H.323||DTLS-SRTP||Unknown||H.264 Full-HD 1080p video rx/tx, Two independent lines supporting Call Control and 3-Party videoconference in Continuous Presence, G.722.1/C wideband audio, Call recording/export, DV/HDMI/Component capture, Presentation (H.239, RFC-4796), Encryption, Far End Camera Control, GPU accel (D3D and OpenGL)||7.0.24; May 26, 2010, discontinued|
|Mumble||Linux, macOS, iOS, Windows, Android||New BSD license||Free||ICE||CELT, Speex, Opus||TLS and OCB-AES128||No max (limited only by server bandwidth and memory)||Chat with (limited) embedded HTML, Automatic Gain Control, very low latency, Access Control Lists for user management, Customizable In-Game Overlay for OpenGL and DirectX, Directional Audio, Plugin Support, Nested Channels, Echo cancellation for headset free use, Global Public Server List, Logitech G15 support, Push-To-Talk and Voice-Activation||1.2.19; January 27, 2017|
|Nymgo||Windows, Android, iOS||Proprietary||Free||SIP, RTP and RTCP||Unknown||Yes||No||Address Book integration, Call recording/export, Mute, On Hold, Caller ID definition||4.2.9; March 2013|
|oovoo||macOS, iOS, Windows, Android||Proprietary||Free||SIP, RTP and RTCP||Unknown||Yes||12||Address Book integration, Call recording/export, Mute, On Hold, Caller ID definition||4.2.9; March 2013|
|Phoner||Windows||Proprietary||Free||SIP, TAPI, CAPI||G.711a, G.711u, G.722, G.726, G.729, GSM, iLBC, speex, Opus||TLS, SRTP, ZRTP||8||Conferencing, call redirection, call recording||3.21 (18 January 2019[±])|
|PhonerLite||Windows||Proprietary||Free||SIP||G.711a, G.711u, G.722, G.726, G.729, GSM, iLBC, speex, Opus||TLS, SRTP, ZRTP||8||Conferencing, call redirection, call recording||2.70 (10 January 2019[±])|
|QuteCom||Linux, macOS, Windows XP-2000||GPL||Free||SIP||G.711, G.729, iLBC, AMR-NB, G.722, Speex, AMR-WB (G.722.2), H.263, H.263+, H.264, Dirac||SRTP, but key exchange via Everbee key Exchange which is not a Standard||Unknown||Video, IM (MSN, AIM, ICQ, Yahoo!, XMPP, Google Talk), voicemail, wengo to phone, conferencing.||2.2.1 (22 June 2011) [±]|
|Ring by Savoir-faire Linux||Android, FreeBSD, iOS, iPhone, Linux, Microsoft Windows, OS X||GPL3||Free||SIP, RTP, STUN per account, SRV, DHT, P2P||Audio: Opus, Speex, G.722, G.711, GSM, VP8, G.729, iLBC. Video: H.264, H.263, VP8, MPEG-4||Voice encryption (SRTP with SDES or ZRTP) and signaling encryption (TLS), multiple realms authentication mechanism||No limit||Blockchain ID-management, Gnome-KDE client, address book, multiple accounts, unlimited call number, call transfer, call hold-unhold, call recording, multi-way conferencing||Android 20190228 (February 28, 2019) [±]|
|Roger Wilco GameSpy||Windows||Proprietary||?||Proprietary||?||?||?||?||2001|
|Skype||Linux(with limited functionality), macOS, Windows 2000-XP-Vista-7-Mobile (unsupported), BREW, Windows Phone , Android, iPhone, PSP||Proprietary||Free||Proprietary P2P protocol [a]||SILK||TLS||25 starting with version 126.96.36.199. 10 with 2.x||Conferencing, video, file transfer, voicemail, Skype to phone, phone to Skype, additional P2P extensions (games, whiteboard, etc...); depending on platform.|
|TeamSpeak||Linux, Windows, macOS, FreeBSD, Android, iOS||Proprietary||Free||Unknown||CELT, Speex, Opus||Yes||32 unlicensed, 512 with non-profit license, 2000||Simultaneous server conferencing with tabs, 3D sound effects, scalable permissions system, firewall friendly file transfers, in-game overlay for DirectX & OpenGL games, global public server list, plugin system||3.1.8|
|TeamTalk||Linux, Windows, macOS, Android, iOS, Raspbian||Proprietary||Free||Proprietary||Opus, Speex, WebM||No||1000||Video, file sharing, desktop sharing, stream media files (MP3, AVI)||5.1.3; May 2016|
|TeamViewer||Linux, Windows, macOS, iOS, Android||Proprietary||Free (personal use only)||Unknown||Unknown||AES256||Unknown||Unknown|
|Telephone||macOS 10.10.2||BSD||Free||SIP, STUN, ICE||Unknown||No||Unknown||Address Book integration||1.1.4; March 6, 2012|
|Toktumi Unlimited, Line2 Pro||Windows XP-Vista-7, macOS, iOS, Android||Proprietary||Free||Proprietary with SIP core||Unknown||Unknown||20||Conferencing, voicemail, caller ID, call-waiting, address book integration; auto-attendant, call-forwarding||Windows; August 2010; macOS; October 2010|
|Tox||Linux, macOS, Windows, Android, FreeBSD||GPL||Free||Tox, VP8||Opus,||NaCl||Unknown||Voice, video, instant messaging, file transfers||Unknown|
|Tru App||Windows 2000-XP-Vista-7, macOS, Linux
iOS, Android, Symbian, BlackBerry OS,
|Proprietary||Free||SIP, XMPP||Unknown||Unknown||Unknown||Chat, file transfer, voicemail, inbound numbers, integration with GTalk, Microsoft Live, Skype|
|Tuenti||Android, iPhone, Windows Phone||Proprietary||Free||WebRTC, SIP, XMPP||iLBC, Opus||Yes||?||Voice, video, Instant messaging, group chat, photo and video sharing, SMS and MMS, native and social network contacts integration, incoming call/IM push notifications.|
|Twinkle||Linux||GPL||Free||SIP||G.711 A-law μ-law, G.726, GSM, iLBC, Speex narrow wide ultrawide||SRTP, ZRTP||3||Conferencing, chat, file transfer, Firefox integration, call redirection, voicemail, support of VoIP-to-Phone services||1.10.0 (July 15, 2016[±])|
|Ventrilo||macOS, Windows, iOS, Android||Proprietary||Free||Unknown||Unknown||No||8||Conferencing, chat, text-to-speech||3.0.8|
|Viber||Linux,[b] macOS,[b] Windows,[b] Android, Bada, BlackBerry OS, iOS, Series 40, Symbian, Windows Phone||Proprietary||?||Unknown||Unknown||Yes||Unknown||Varies by platform: Text, picture and video messaging on all, voice calling only on iPhone, Android and Microsoft's Windows Phone|
|Wire||Linux, Windows, macOS, iOS, Android, Web||GPLv3||Free||?||Template:Opus (audio), VP8 (video)||DTLS, SRTP||10||End-to-end encryption by default for everything, instant messaging, video call, video group call, file sharing, GIF sharing, push to talk, edit message, delete message (on both side), timed messages, doodling, identity verification, screen sharing (desktop only)||?|
|X-Lite||macOS, Windows||Proprietary||Free||SIP, STUN, ICE, TURN||H.263, H.263+, G.711, iLBC, Speex||No||3||VoIP over WiFi, 3G, 4G, video, instant messaging, presence (SIP SIMPLE), call waiting, call hold, call forwarding, voice mail, message waiting indication, 3 way conferencing, contacts integration, background noise reduction (BNR), automatic gain control (AGC)||5.3.3 July 10, 2018|
|Yahoo! Messenger||Classic Mac OS (8, 9), macOS, Windows, (Linux, FreeBSD version VoIP incapable)||Proprietary||Free||SIP (using TLS) and RTP (media)||Unknown||Unknown||Unknown||Video, file transfer, PC to phone, phone to PC||Windows: 188.8.131.52; May 31, 2012|
Mac: 3.0.1; July 20, 2011
Linux: 1.0.6; September 2003
SunOS 5.7: 0.99.17-1; September 2003
Solaris 8: 1.0.4; September 2003
FreeBSD 4-5: 1.0.4; September 2003
iOS: 2.2.6; July 12, 2012
|Yate Client||Linux, macOS, Windows||GPL||Free||SIP, IAX, XMPP, H.323||G.711a, G.711u, GSM 06.10, iLBC, Speex, G.723, G.726, G.728, G.729||SRTP, maybe ZRTP?||Unknown||6.0.0; September 2017|
|Zfone||Linux, macOS, Windows||Viewable source||Includes time bomb provision||SIP, RTP||Unknown||SRTP, ZRTP||Unknown||Beta 2008-09-04 (Linux 0.9.224), (macOS 0.9.246), (Windows 0.9.206)|
- It is possible to connect by SIP to the Skype network via additional "Skype Connect" PBX software and alternative (SIP) client software/hardware. Neither the Skype software nor the Skype network supports SIP directly
- Viber must be first installed on a mobile phone to function on a desktop operating system
Discontinued softphone service
For mobile VoIP clients:
|Program||Operating systems||License||Open source||Protocols||Codecs||Encryption||Other abilities||Latest release|
|Acrobits Softphone||Android v2.2+, iOS v7.0+||Proprietary||No||SIP||G.711, G.722, iLBC, GSM, G.729||TLS, SRTP, ZRTP||VOIP over Wi-Fi or 3G iOS only: push notifications, video, number rewriting, address book matching, sms for betamax providers and pennytel||Acrobits Softphone: 3.20 (Android), 5.2 (iOS)|
|CounterPath Corporation Bria||Android v4.4+, iOS v10+||Proprietary||No||SIP||G.722 wideband, G.711a, G.711u, iLBC, G.729a, SILK, GSM, VP8, H.264, Opus||TLS, SRTP, ZRTP||Voice and video calling, SIP and XMPP messaging support, group chat, file, image and document sharing, contact integration, incoming call/IM push notifications.||5.3.4 July 23, 2018|
|CSipSimple||Android||GPL||Yes||SIP||Opus, AMR-WB, G.722, iSAC, iLBC, Speex, Silk, Codec2, G.726, G711 (PCMA & PCMU), AMR, GSM||SRTP, SIP over TLS 1.0 and ZRTP||?||1.02.02|
|Google Duo||iOS, Android||Proprietary, freeware||No||WebRTC||?||?||One-to-one voice and video calling.|
|iCall Mobile||iOS v4.3+||Proprietary, freeware||No||SIP AIM ICQ XMPP, Facebook, Yahoo! Messenger, Windows Live||Speex, CELT, WebM||TLS, ZRTP||VoIP over Wi-Fi or 3G, SMS, voicemail||2.0.1; April 2012|
|Jajah Mobile Web||Symbian, Windows Mobile (version unknown)||Proprietary||No||?||?||?||web based service, Call back,no download||?|
|JusTex by Juphoon||Android, iOS v5.1+||Proprietary||No||SIP||PCMA, PCMU, G.722, iLBC, iSAC, Opus, H.264, VP8, H.263||TLS, TCP, UDP, SRTP||JusTex Softphone over Wi-Fi or 3G, HD voice and video call, Multiparty call, conference.||3.0.1 (iOS); July 13, 2014; 3.0 (Android); July 9, 2014|
|Line2||Android, iOS||Proprietary, freeware||No||Proprietary with SIP core||?||?||Tri-mode calling (cellular, 3G/4G data, Wi-Fi), SMS over IP, visual voicemail, 20-person conference calls, auto-attendant, call-forwarding||1.0.4 Android, 3.2.1 iOS|
|Media5-fone||iOS, Android||Proprietary||No||SIP||PCMA, PCMU, G.722*, iLBC, iSAC*, G.729*||TLS*, SRTP*||Wi-Fi and 3G/4G data, second call*, conference calls*, HD Voice, Bluetooth* (* Additional fees)||?|
|Signal by Signal Messenger||iOS, Android||GPLv3||Yes||WebRTC||Opus||TLS, Signal Protocol||End-to-end encryption by default for everything. CallKit and location privacy, one-to-one and group messaging, video calling, image/video sharing, timed messages, identity verification, screenshot blocking. Android only: SMS/MMS messaging, doodling, GIF sharing.||Android v4.35.3 (March 22, 2019) [±]|
|Sipdroid||Android||GPL||Yes||SIP||?||?||Uses Wi-Fi, 3G or EDGE||2.7|
|Tango by TangoME Inc.||iOS, Android, Microsoft Windows, macOS, Windows Phone||Proprietary, freeware||?||?||?||?||VoIP, Wi-Fi out & in, SMS over IP, call-through & call-back, instant messaging, videoconferencing||?|
|Truphone||Nokia-Symbian, iOS, Android, BlackBerry||Proprietary, freeware||No||SIP||?||?||VoIP, Wi-Fi out & in, SMS over IP, call-through & call-back, connection management, provisioning||Symbian 4.0, iOS 1.11.1|
|Vopium||Symbian, Java ME, Android, BlackBerry RIM, iOS, Windows Mobile 2003 SE and higher||Proprietary, freeware||No||SIP, MSN, Skype, Yahoo, AOL, ICQ, Google Talk, Facebook & Twitter||GSM||?||Wi-Fi VoIP, GSM call-through, SMS over IP, least cost routing, synchronising-backup mobile contacts and calendar||2.0|
Android, BlackBerry, iOS, Symbian, Windows Phone
|Proprietary, freeware||No||?||?||ECDH, SRTP||VoIP and instant messaging over Wi-Fi or a data connection.|
|Windows Mobile 6||Windows Mobile 6 Professional/Standard||Proprietary||No||SIP to publicly and non-publicly routable servers||?||?||Wi-Fi Mobile VoIP||6.1|
|X-PRO for Pocket PC||Windows Mobile 2003 (earlier versions support Windows PocketPC 2002)||Proprietary, discontinued in April 2007||No||SIP||?||?||Supported devices: AudioVox Maestro, Compaq/HP iPAQ: 365x, 37xx, 385x, 395x, hx4700, Dell Axim X51, X51v, Toshiba e550, e570. iPAQ 545x and Toshiba e7xx are not supported.||2.2|
|Yuilop||Android, iOS, Windows Phone, BlackBerry OS||Proprietary, freeware||No||XMPP, RTP||iLBC||TLS||VoIP over 3G-4G-LTE and Wi-fi, SMS, group chat, photo sharing, Location sharing, virtual phone numbers||iOS 2.4 (November 26, 2014) [±]|
Android 2.0.2 (February 12, 2014[±]
Frameworks and libraries
|Program||Operating systems||License||Protocols, based on, compatible with||Encryption||Other abilities||Key and target markets||Latest release|
|Tapioca||Linux||GPL||Telepathy (software)||No||0.3.9; June 12, 2006|
|Telepathy, Farstream||Linux, macOS, Windows||LGPL||SIP, XMPP (Jingle), ICE (STUN/TURN), UPnP||No||Multi-user A/V conferencing, IM, collaborative applications||Mobile devices (Maemo, Meego), Linux desktop or embedded||spec 0.27.2; September 24, 2013|
|OPAL||Windows, Linux (including embedded variants), macOS||MPL||SIP, H.323, IAX2, CAPI, VXML||Unknown||Multi-user A/V conferencing, IM, IVR||Softphones, softswitches, telephony application servers||3.14.3; October 10, 2014|
|GNU oSIP||Linux, Windows, macOS, Android, iPhone, BlackBerry||LGPL||SIP, SDP||Unknown||Multi-user A/V conferencing, IM, IVR||Softphones, embedded and mobile devices, telephony application servers||4.1.0; December 18, 2013|
|Program||Operating systems||License||Protocols, based on, compatible with||Encryption||Other abilities||Key and target markets||Latest release|
|3CX Phone System||Windows, Linux||Proprietary||SIP||TLS, SRTP||Voice and video IP telephony and conferencing, voice mail and instant messaging||< 50,000 users||15.5 ; June 7, 2017|
|AS5300||Linux, Windows Server 2003||Proprietary||SIP, UNIStim, MLPP||SSL, TLS,
|Voice and Video IP telephony, Voice and Video conferencing, voice mail and instant messaging||1,000 - 25,000 users||1.0; January 2008|
|AskoziaPBX||no additional OS required (Linux based)||GPL, Open core||SIP, H.323, IAX, SCCP||No||ISDN, analog, Voicemail, Conferencing, MOH, ACD, IVR, Call forwarding, Call recording||SMEs up to 50 users||2.2.2; December 2012|
|Asterisk PBX||Linux, BSD, macOS, Solaris||GPL, optional: Proprietary||SIP, H.323, IAX, MGCP, VOFR, XMPP, Google Talk, TDM||TLS, SRTP||VoIP Gateway, voicemail, basic accounting (can be expanded by interface with ODBC-compliant database), billing, conferencing, hot-desking, IVR trees with conditional logic, call queuing, automated call distribution||Enthusiasts, developers, enterprise users (capacity dependent on server design, scalable across multiple servers)||16.1.1 (26 December 2018) [±]
|Brekeke SIP Server||Linux, Windows||Proprietary||SIP||TLS, SRTP||SIP Registrar, SIP Proxy||SIP Service Providers, VoIP service providers, Healthcare, Security||184.108.40.206; December 21, 2018|
|Brekeke PBX||Linux, Windows||Proprietary||SIP||TLS, SRTP||Voice and Video IP telephony, Voice and Video conferencing, and voice mail||Hosted service providers, Mid-large enterprise||220.127.116.11; December 27, 2018|
|CallMax Softswitch||Linux||Proprietary||SIP, H.323||SSL, TLS, HTTPS||Integrated billing, IP PBX Platform, Calling card platform, Callshop module, Customer Web Portal, Retail SMS Platform.||SIP Service Providers, Residential & Business VoIP providers, Corporate Clients, Other Class 5 softswitch users||3.6; October 2015|
|CommuniGate Pro||Linux, BSD, macOS, Windows, Solaris, HPUX, AIX||Proprietary||SIP, XIMSS Protocol, XMPP, WebRTC||SSL, TLS, SRTP||SIP Registrar/Proxy, Authentication, Diameter, RADIUS, ENUM, many others||Carriers, enterprises, MNOs, ISPs, SaaS providers||6.1.11; June 2016|
|Dial-Gate Softswitch PBX||Linux, Windows||Proprietary||SIP||TLS, SRTP||Billing server, real-time account and line monitoring, web-based user interface||Softswitch users, service providers||4.3; June 2014|
|Dial-Office IP-PBX||Linux, Windows||Proprietary||SIP||TLS, SRTP||Unified Communications, Conferencing, remote worker support and voice mail||Small businesses, Mid-large enterprises||4.1; December 2013|
|Elastix||Linux||GPL||SIP, IAX, H323, XMPP||TLS, SRTP||Unified communication server that also supports chat, mail and fax.||Capacity dependent on server design, scalable across multiple servers||2.5.0 (stable), 3.0.0 (stable), 4.0.0 (stable); February 10, 2016|
|FreeSWITCH||Linux, BSD, macOS, Solaris, Windows||Mozilla Public License||SIP, NAT-PMP, STUN, SIMPLE, XMPP, Google Talk (Jingle), IAX, H.323, MRCP, RSS, Skype||TLS, SRTP, ZRTP||Recording, Voicemail, Conferencing, RADIUS, ENUM, IM Proxy, Streaming, Media gateway, Soft-PBX, IVR (modular)||Large soft-switch users, home PBX users, softphone users||1.8.5 (January 24, 2019[±])|
|FreePBX||Linux, BSD, Solaris||GPL||SIP, IAX, H323, XMPP||TLS, SRTP||Complete PABX Service, based on Asterisk and PHP 5.6; provides a full replacement for a legacy non-VoIP phone system; under current and active development||Scales from Raspberry PI (3 users) to multiple parallel clusters (10K+ simultaneous calls)||14.0; August 2017|
|GNU Gatekeeper||Linux, FreeBSD, macOS, Windows XP-2000-Vista-7||GPL||H.323||H.235||H.460.18 firewall traversal, routing, accounting||video conferencing, VoIP carriers large and small||3.7; August 15, 2014|
|HERO Hosted PBX||Linux, Windows||Proprietary||SIP||TLS, SRTP||Unified Communications, billing server, cloud-based management and web interface||Mid-large enterprises, VoIP carriers and service providers, telecom operators||4.3; December 2013|
|Kerio Operator||Linux, VM||Proprietary||SIP||SSL, TLS, SRTP||integrated firewall, Auto attendant, Call queues, Conference calling, Call forwarding, pickup, parking, recording, Click to Call, Video calling, Fax support, Paging, Salesforce.com and CRM integration, Voicemail to email, complementary desktop Softphone app||SME||2.5.2; November 15, 2016|
|MediaCore SBC||Linux||Proprietary||H.323, SIP, SMPP||SSL, TLS, HTTPS||Dynamic routing mechanism including LCR, Jurisdictional routing support, A-number based routing for EU-based providers), integrated billing, SIP-H.323 protocol converter, Transcoding - codec converter module, Guardian - revenue assurance module, SBC functionality, full and media proxy, Carrier SMS support||Transit VoIP services providers, VoIP wholesale carriers, VoIP termination providers, SMS carriers||4.6.1; May 2017|
|Murmur||Linux, BSD, macOS, Windows||BSD, GPL||CELT, Speex, Opus||TLS||Chat with (limited) embedded HTML, ACLs for user management, Customizable In-Game Overlay, Directional Audio, Plugin Support, Nested Channels||Individuals to Small and medium enterprise (25-5000 users)||1.2.17; September 24, 2016|
|Mysipswitch||Linux||BSD||SIP, Ajax||SSL||SIP proxy server which allows the use of multiple SIP accounts with a single SIP login||Individuals||August 2007|
|Objectworld UC Server||Windows XP-2003-2008||Proprietary||SIP||No||IP PBX, personal assistants, IVR, automated phone provisioning, fax server, unified messaging, Outlook, Exchange and Lotus Domino-Notes integration, conferencing, outbound dialing||Small and medium enterprise (25-2000 users)||4.4.2; May 2009|
|Kamailio, OpenSIPS (formerly named OpenSER)||Linux, BSD, Solaris||GPL||SIP, XMPP||TLS, SRTP||SIP registrar-proxy, authentication, Diameter, RADIUS, ENUM, least-cost-routing, many others||SIP Service Providers||4.0.1 (25 April 2013[±])|
|Pbxnsip||Linux, BSD, macOS, Windows||Proprietary||SIP||SRTP||IP PBX, presence indication, IVR, automated phone provisioning, fax server, unified messaging, Outlook, Exchange integration, conferencing, outbound dialing||Small and medium enterprise (25-256 users)||18.104.22.16877; April 2009|
|SIP Express Router (SER)||Linux, BSD, Solaris||GPL||SIP||No||SIP Registrar/Proxy, Authentication, Diameter, RADIUS, ENUM, many others||SIP Service Providers||2.0.0 Ottendorf|
|sipXecs IP PBX||Linux||AGPL||Native SIP call control, XMPP||TLS, SRTP||Full redundancy (HA), instant messaging, voicemail, user portal, admin GUI, plug & play management including phones and gateways, fully featured||Enterprises between 10 and 10,000 users, multi-site||14.04.2; July 2014|
|vzRoom||Windows||Proprietary||SIP||SSL, TLS, AES||Instant messaging-chat, VoIP, video, sharing (desktop, video, file), whiteboard, scheduler, recording||Individual to small and medium enterprise (2-1,000 users)||0.8.8.735; November 2010|
|Yate||BSD, Linux, macOS, Windows||GPL||SIP, IAX, H.323, ISDN, XMPP (Jabber), Jingle (Google Talk), MGCP, SS7 over IP, Cisco SLT (Signalling Link Transport) (SS7 MTP2 backhaul over IP), SCTP, SCCP, TCAP, MAP CAMEL||SSL, TLS, SRTP||Voice, video, file transfer, data, H323 to SIP signalling proxy, instant messaging, IVR, PC2Phone and Phone2PC gateway, SCCP — GTT routing between networks, Secure Unified Communications, SIP registrar-proxy, SIP SBC (session border controller), USSD, voicemail, VoIP, VoIP to PSTN gateway, conference server (max 200 voice channels per conference), call centre server, prepaid and postpaid cards||Deployed on home servers and large networks with millions of users||5.5; May 2015|
Secure VoIP software
This section needs expansion. You can help by adding to it. (July 2016)
VoIP software with client-to-client encryption
The following table is an overview of those VoIP clients which provide end-to-end encryption.
|Client name||Development status||Open source client||End-to-end authentication[a]||Encryption protocols||Forward secrecy||Multiple encryption||Encrypted group calling||Proxy, Tor|
|Silent Phone||Active||Viewable source||Yes||Yes||?||?||Yes||Yes||Yes||Yes||No|
VoIP software with client-to-server encryption
The following table is an overview of those VoIP clients which provide client-to-server encryption.
|Client name||Encryption protocols|
|Skype||A custom protocol|
- End-to-end authentication protects communications from man-in-the-middle attacks by the service provider.
- Only if the user has registered with a compatible SIP provider. Some SIP providers do not support certain encryption protocols.
- Only the encryption related source code is open.
- Only on the network connection, not on the end-to-end layer.
- List of codecs
- List of SIP software
- List of video telecommunication services and product brands
- Matrix (communication protocol)
- Comparison of audio coding formats
- Comparison of instant messaging clients
- Secure communication
- "Skype Connect..." skype.com. Microsoft Corporation Inc. Archived from the original on 2014-11-11. Retrieved 15 November 2014.
- "Download Blink". Blink Project's Website. Retrieved 22 June 2016.
- "Release Notes for Cisco IP Communicator 8.6.6". Cisco. Retrieved 2018-04-03.
- "Cisco IP Communicator 8.6". Cisco. Retrieved 2018-04-03.
- "Discord on Twitter". Twitter. Retrieved 2016-12-29.
- "Ekiga 4.0.1 [STABLE] available". www.ekiga.org. 21 February 2013. Retrieved 2014-05-09.
- "Telepathy Q&A from the Boston GNOME Summit". Retrieved 4 February 2014.
- "ANNOUNCE: Empathy 3.12.12". 13 May 2016. Retrieved 17 August 2016.
- Eyeball Chat 3.2 Features. EyeballlChat.com.
- "Chrome Web Store Hangouts". Retrieved July 11, 2013.
- "Telephony with Lotus Sametime software". IBM.com. Retrieved 2010-02-16
- "Jitsi (SIP Communicator) Android — Nightly Builds Index". Jitsi.org. Retrieved 2014-11-15.
- Interview with Emil Ivov, Deploy360 blog
- "[#JITSI-1166] P2P IPv6 calls still do not work with explicit IPv6 addresses, no matter if brackets are used — Java.net JIRA". Java.net. Retrieved 2014-02-13.
- Release history on Phoner download page
- Changelog on PhonerLite download page
- "Supported Codecs". qutecom.org. Retrieved 19 December 2014.
- "Announcement: QuteCom 2.2.1". Archived from the original on 2 April 2013.CS1 maint: Unfit url (link)
- "News". Ring. 2018-07-25. Retrieved 2018-12-01.
- Savoir-faire Linux Inc. (25 November 2018). "Ring". Google Play. Google. Retrieved 1 December 2018.
- Savoir-faire Linux Inc. (20 August 2018). "Index of _ring-manual". dl.ring.cx. Retrieved 1 December 2018.
- Savoir-faire Linux Inc. (26 November 2018). "Ring - a GNU package". App Store. Apple. Retrieved 1 December 2018.
- "Release Notes for Skype for Windows, Mac and Linux". Skype Support.
- "Release Notes for Skype on Mobile". Skype Support.
- "New TeamSpeak3 Client and Server released today". TeamSpeak Systems GmbH. Retrieved 2015-08-04.
- "TeamViewer overview". GetApp.
- "TeamViewer". TeamViewer. 20 March 2019.
- "TeamViewer for Mac". TeamViewer. 20 March 2019.
- "TeamViewer". TeamViewer. 20 March 2019.
- "TeamViewer". GooglePlay. Google. Retrieved 20 March 2019.
- "TeamViewer: Remote Control". App Store. Apple. Retrieved 22 January 2019.
- "TeamViewer: Remote Control". Windows Store. Microsoft. Retrieved 20 March 2019.
- "TeamViewer: Remote Control". BlackBerry World. BlackBerry Limited. Retrieved 18 December 2017.
- "TeamViewer". Chrome Web Store. Google. Retrieved 15 November 2018.
- Brad Chacos, Brad. "Hands on with Viber's new desktop app: It's no Skype". www.pcworld.com. IDG Consumer & SMB. Archived from the original on 2014-07-25. Retrieved 15 November 2014.
If you don’t have Viber on your phone and try to install the service on your PC, the app will redirect you to its website and ask you to install Viber on your phone first.
- Viber Unveils Desktop App
- Lunden, Ingrid (19 April 2016). "Viber adds end-to-end encryption and hidden chats as the messaging app privacy wave grows". TechCrunch. AOL Inc. Retrieved 12 July 2016.
- Viber Media S.à r.l. (13 June 2017). "Viber - Android Apps on Google Play". Google Play. Google. Retrieved 19 June 2017.
- Viber Media, Inc (13 June 2017). "Viber On the App Store on iTunes". App Store. Apple. Retrieved 19 June 2017.
- Viber Media (2018-04-26). "Viber". Windows Phone Marketplace. Retrieved 2018-04-26.
- Viber Media (23 April 2014). "Viber 10 - BlackBerry World". BlackBerry App World. Research In Motion (RIM). Retrieved 20 April 2016.
- "Wire Security Whitepaper". Wire Swiss GmbH. Retrieved 13 April 2016.
- "Wire on Twitter". Twitter. Retrieved 2017-02-28.
- "Google Duo". APKMirror. Android Police. March 11, 2018. Retrieved March 11, 2018.
- "Google Duo - Video Calling". App Store. Apple Inc. March 11, 2018. Retrieved March 11, 2018.
- "JAJAH.Mobile Web" Archived 2009-06-29 at the Wayback Machine. Jajah.com.
- Marlinspike, Moxie (14 February 2017). "Video calls for Signal now in public beta". Open Whisper Systems. Retrieved 22 March 2017.
- Marlinspike, Moxie (13 March 2017). "Video calls for Signal out of beta". Open Whisper Systems. Retrieved 22 March 2017.
- Marlinspike, Moxie (21 December 2016). "Doodles, stickers, and censorship circumvention for Signal Android". Open Whisper Systems. Retrieved 22 March 2017.
- Marlinspike, Moxie (1 November 2016). "Signal and GIPHY". Open Whisper Systems. Retrieved 22 March 2017.
- Signal Foundation (22 March 2019). "Signal – Private Messenger". Google Play. Google. Retrieved 23 March 2019.
- Open Whisper Systems (7 February 2019). "Releases - signalapp/Signal-Android". GitHub. Retrieved 12 February 2019.
- Open Whisper Systems (6 February 2019). "Signal - Private Messenger". App Store. Apple. Retrieved 12 February 2019.
- Open Whisper Systems (21 March 2019). "Releases - signalapp/Signal-Desktop". GitHub. Retrieved 23 March 2019.
- "WhatsApp Encryption Overview – Technical white paper" (PDF). WhatsApp Inc. 4 April 2016. Retrieved 9 April 2016.
- WhatsApp Inc. (14 January 2019). "WhatsApp Messenger". App Store. Apple. Retrieved 14 January 2019.
- WhatsApp Inc. (14 December 2018). "WhatsApp Messenger". Apkmirror.com. Android Police. Retrieved 14 December 2018.
- WhatsApp Inc. "WhatsApp Messenger". Windows Store. Microsoft. Retrieved 7 April 2018.
- WhatsApp Inc. "WhatsApp for Nokia S60". whatsapp.com. WhatsApp Inc. Retrieved 4 April 2017.
- WhatsApp Inc. (26 June 2017). "WhatsApp Messenger". BlackBerry World. BlackBerry. Retrieved 7 August 2017.
- "Pocket PC SIP Softphone". Counterpath.com.
- "Recommended Pocket PCs". Counterpath.com.
- "yuilop - Free texts and SMS". Amazon. Retrieved 10 March 2014.
- "Asterisk Commercial Licensing". Digium. Retrieved 12 October 2013
- "ChangeLog-16-current". Retrieved 30 December 2018.
- "ChangeLog-15-current". Retrieved 30 December 2018.
- "ChangeLog-13-current". Retrieved 30 December 2018.
- "Secure Messaging Scorecard. Which apps and tools actually keep your messages safe?". Electronic Frontier Foundation. 4 November 2014. Retrieved 11 July 2016.
- ""Letter Sealing" End-to-End Encryption Indicator Icon Introduced to LINE Messaging App". Line Corporation. 10 August 2016. Retrieved 29 September 2016.
- Shin, Ki Bin (11 August 2016). "The next step for even safer messaging: Letter Sealing". Line Corporation. Retrieved 30 September 2016.
- "PGPfone". pgpi.org. n.d. Retrieved 26 August 2016.
- Marlinspike, Moxie (13 March 2017). "Video calls for Signal out of beta". Open Whisper Systems. Retrieved 30 March 2017.
- "Is Silent Phone open source?". silentcircle.com. Silent Circle. n.d. Retrieved 26 August 2016.
- "Voice Calls: Secure, Crystal-Clear, AI-Powered". Telegram. 30 March 2017. Retrieved 30 March 2017.
- "Where can I find Threema's source code?". threema.ch. Threema. n.d. Retrieved 30 October 2017.
- "Threema cryptography whitepaper" (PDF). threema.ch. Threema. n.d. Retrieved 30 October 2017.
- "WhatsApp Encryption Overview – Technical white paper" (PDF). WhatsApp Inc. 4 April 2016. Retrieved 5 April 2016.
- "A major upgrade to calling". Medium. Wire Swiss GmbH. 14 March 2017. Retrieved 14 March 2017.
- "Is Zfone open source?". zfoneproject.com. Zfone. 2006. Retrieved 26 August 2016.
- "Do you support Elliptic Curve Diffie-Hellman?". zfoneproject.com. Zfone. 2006. Retrieved 26 August 2016.
- "Why do we need ZRTP if we already have SRTP? Isn't SRTP good enough?". zfoneproject.com. Zfone. 2006. Retrieved 26 August 2016.