View source for Comparison of VoIP software

{{short description|Software comparison}}

This is '''a comparison of voice over IP (VoIP) software''' that examines applications and systems used for conducting voice and multimedia communications across Internet Protocol (IP) networks. VoIP technology has transformed telecommunications by offering alternatives to traditional telephony systems while providing enhanced features and cost savings.

For residential users, '''VoIP services''' typically provide significant cost advantages compared to traditional '''public switched telephone network (PSTN)''' services. These systems eliminate geographic restrictions on phone numbers, enabling users to maintain local numbers in any area code regardless of their physical location. For example, a user can operate a New York phone number while residing in Tokyo, facilitating global mobility and reducing international communication costs.

In enterprise environments, VoIP technology enables the consolidation of voice and data networks into a unified IP infrastructure. This consolidation eliminates the need for separate voice and data pipelines while providing '''advanced capabilities''' including:

* Unified communications integration
* Presence management systems
* Advanced call routing
* Mobile device integration
* Multimedia conferencing capabilities

Softphone applications serve as the primary client-side implementation of VoIP technology. These applications transform standard computing devices into full-featured communication endpoints, supporting voice and video calls over IP networks while providing standard telephony functions. Most softphone clients utilize the Session Initiation Protocol (SIP), an open standard that supports various audio and video codecs. Some systems, like Skype, operate on proprietary protocols but can integrate with SIP-based systems through specialized business telephone system (PBX) software.

The VoIP ecosystem encompasses various specialized applications beyond basic communication endpoints:

== Core components ==
{{Unsourced|section|date=January 2025}}
* Conferencing servers for large-scale virtual meetings
* Intercom systems for internal communications  
* Virtual foreign exchange services (FXOs)
* Hybrid systems supporting both VoIP and PSTN integration

== Specialized applications ==
{{Unsourced|section|date=January 2025}}
* Interactive Voice Response (IVR) systems
* Automated dictation platforms
* Professional call recording solutions
* Custom hold music and messaging systems

VoIP implementations generally fall into two categories:

* Web-based solutions that operate through browsers, offering simplified deployment and platform independence

* Standalone desktop applications that provide enhanced features, superior reliability, and advanced feature sets

== Desktop applications ==
<!-- ########## EDITORS TAKE NOTE ###########

In the "License" column, please restrict entries to:
* {{open source|[[LicenseFreeType|abbreviation]]}}
* {{proprietary}}
* {{some|Mixed: [[LicenseFreeType|abbreviation]], [[Proprietary software|proprietary]]}} or {{some|Mixed: [[Proprietary software|proprietary]], [[LicenseFreeType|abbreviation]]}} depending on which form dominates

ADD NO LINKS TO WEBSITES. ENTRIES WILL BE REMOVED AS LINK SPAM. SPA Accounts are especially obvious in this section.

-->
{{sort-under}}
{| class="wikitable sortable sort-under"
|-
! Program
! [[Operating system]]s
! [[Software license|License]]
! Costs
! [[Communications protocol|Protocols]]
! [[Codec]]s
! [[Encryption]]
! Max conference peers
! Other abilities
! Latest release
|-
!{{rh}}| [[Blink (SIP client)|Blink]]
| [[Linux]], [[macOS]], [[Microsoft Windows|Windows]]
| {{some|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
| [[Interactive Connectivity Establishment|ICE]], [[Session Initiation Protocol|SIP]], [[Message Session Relay Protocol|MSRP]], [[RFB protocol|RFB (VNC)]], [[XCAP]]
| [[Opus (audio codec)|Opus]], [[speex]], [[G.722]], [[GSM]], [[iLBC]], [[PCMU]], [[A-law algorithm|PCMA]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]] and [[ZRTP]] on all versions, [[Off-the-Record Messaging|OTR/SMP]] on Linux and macOS only<ref>{{cite web|title=Download Blink|url=http://icanblink.com/download/|website=Blink Project's Website|date=14 January 2016|access-date=22 June 2016}}</ref>}}
| No limit
| IM, file transfer, desktop sharing, multi-party conference, wideband
| Blink Qt <!--{{Start date and age|201y|mm|dd}}-->
|-
!{{rh}}| [[Battle.net]]
| [[macOS]], [[Android (operating system)|Android]], [[iOS]], [[Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| {{Unk}}
| {{Unk}}
| {{Unk}}
| {{Unk}}
| IM, multi-party conference
| {{Unk}}
|-
!{{rh}}|  [[Discord (software)|Discord]]
| [[macOS]], [[Android (operating system)|Android]], [[iOS]], [[Windows]], [[Linux]]
| {{proprietary}}
| {{free}}, Premium "Nitro" Subscription for Additional Features.
| [[Real-time Transport Protocol|RTP]], [[User Datagram Protocol|UDP]], [[WebSocket|WS]], [[HTTPS]]
| [[Opus (audio codec)|Opus]]
|{{Yes|[[Transport Layer Security|TLS]]}}
|5000 soft limit for voice calls,<ref>{{Cite news|url=https://twitter.com/discordapp/status/814546030612148224|title=Discord on Twitter|newspaper=Twitter|access-date=2016-12-29}}</ref> 25 hard limit for video<ref>{{cite web|url=https://blog.discord.com/wave-hello-to-server-video-85dcef1128f0|title=Wave Hello to Server Video|access-date=2020-06-21}}</ref>
|IM, file sharing, desktop sharing, in-game overlay
|10.0.19045; {{Start date and age|2024|12|19}}
|-
!{{rh}}| [[Eyeball Chat]]
| [[Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[STUN]], [[Interactive Connectivity Establishment|ICE]], [[Extensible Messaging and Presence Protocol|XMPP]]
| {{Unk}}
| {{Yes}}
| 5<ref>{{usurped|1=[https://web.archive.org/web/20090321090148/http://eyeballchat.com/ eyeballchat.com]}}. EyeballChat.com.</ref>
| IM, Conferencing, Voice, Video and [[SIMPLE (instant messaging protocol)|SIMPLE]] based presence
| [[Microsoft Windows|Windows]] 3.2; {{Start date and age|2009}}
|-
!{{rh}}| [[FaceTime]]
| [[iOS]], [[macOS]]
| {{proprietary}}
| {{Free}}
| [[Session Initiation Protocol|SIP]], [[IETF]], Signaling protocol for VoIP, [[STUN]], [[TURN]] and [[Interactive Connectivity Establishment|ICE]]| [[IETF]], technologies for traversing firewalls and [[Network address translation|NAT]]
| [[H.264]] Video, [[AAC-LD|AAC-ELD]] Audio, [[H.263]] and [[VP8]]
| [[Real-time Transport Protocol|RTP]], [[Secure Real-time Transport Protocol|SRTP]] [[IETF]]|standards for delivering real-time and encrypted media streams for VoIP.
| 20
| Video, voice, conferencing, with additional tools available as "Services".
|
|-
!{{rh}}| [[IBM Lotus Sametime|IBM Sametime]]
| [[Linux]], [[macOS]], [[Microsoft Windows|Windows]], mobile
| {{proprietary}}
| {{dunno}}
| [[Session Initiation Protocol|SIP]]-[[SIMPLE (instant messaging protocol)|SIMPLE]], [[T.120]]
| [[H.323]]
| {{Yes|[[Transport Layer Security|TLS]]}}
| {{Unk}}
| IM, File transfer, Voice, Presence, Server stored contact list, HTTP tunneling, plugins, embeddable in [[Lotus Notes]]<ref>[http://www-01.ibm.com/software/lotus/products/sametime/telephony.html "Telephony with Lotus Sametime software"]. IBM.com. Retrieved 2010-02-16</ref>
| 8.5.2; {{Start date and age|2011|05|08}}
|-
!{{rh}}| [[Jami (software)|Jami]]
| [[Android (operating system)|Android]], [[FreeBSD]], [[iOS]], [[iPhone]], [[Linux]], [[Microsoft Windows]], [[OS X]]<ref>{{Cite web|url=https://ring.cx/en/news|title=News|date=2018-07-25|website=Ring|language=en|access-date=2018-12-01|archive-url=https://web.archive.org/web/20181226012459/https://ring.cx/en/news|archive-date=2018-12-26|url-status=dead}}</ref>
| {{open source|[[GNU General Public License|GPL-3.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]], [[STUN]] per account, [[SRV record|SRV]], [[Distributed hash table|DHT]], [[Peer-to-peer|P2P]]
| Audio: [[Opus (audio codec)|Opus]], [[Speex]], [[G.722]], [[G.711]], [[GSM]], [[VP8]], [[G.729]], [[iLBC]]. Video: [[H.264]], [[H.263]], [[VP8]], [[MPEG-4]]
| {{Yes|Voice encryption ([[Secure Real-time Transport Protocol|SRTP]] with [[SDES]] or [[ZRTP]]) and signaling encryption ([[Transport Layer Security|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
| {{Latest_stable_software_release/Ring_(software)}}
|-
!{{rh}}| [[Jitsi]]
| [[Linux]], [[macOS]], [[Microsoft Windows|Windows]] (all java supported). ''Experimental'' [[Android (operating system)|Android]] builds are also available.<ref>{{cite web|url=https://download.jitsi.org/jitsi/nightly/android/|title=Jitsi (SIP Communicator) Android&nbsp;— Nightly Builds Index|publisher=Jitsi.org|access-date=2014-11-15|archive-url=https://web.archive.org/web/20141129035757/https://download.jitsi.org/jitsi/nightly/android/|archive-date=2014-11-29|url-status=dead}}</ref>
| {{open source|[[Apache License|Apache-2.0]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]]-[[SIMPLE (instant messaging protocol)|SIMPLE]], [[Extensible Messaging and Presence Protocol|XMPP]]-[[Jingle (protocol)|Jingle]] [[STUN]] [[Interactive Connectivity Establishment|ICE]], [[Traversal Using Relays around NAT|TURN]]
| [[SILK]], [[G.722]], [[Speex]], [[Opus (audio codec)|Opus]], [[G.711]] (PCMU/PCMA), [[iLBC]], [[GSM]], [[G.729]], [[H.264]], [[H.263]], [[VP8]]
| {{Yes|[[ZRTP]], [[Secure Real-time Transport Protocol|SRTP]], [[Off-the-Record Messaging|OTR]], [[Transport Layer Security|TLS]]}}
| {{Unk}}
| Text messaging, audio-video telephony, IPv6 (often broken,<ref>[http://www.internetsociety.org/deploy360/blog/2013/03/video-emil-ivov-about-jitsi-a-voip-softphone-supporting-ipv6-and-dnssec/ Interview with Emil Ivov], Deploy360 blog</ref> P2P not supported<ref>{{cite web |url=https://java.net/jira/browse/JITSI-1166 |title=[#JITSI-1166&#93; P2P IPv6 calls still do not work with explicit IPv6 addresses, no matter if brackets are used&nbsp;— Java.net JIRA |publisher=Java.net |access-date=2014-02-13 |archive-url=https://web.archive.org/web/20140221210327/https://java.net/jira/browse/JITSI-1166 |archive-date=2014-02-21 |url-status=dead }}</ref>), call recording, 64-bit
| {{Latest stable software release/Jitsi}}
|-
!{{rh}}| [[Linphone]]
| [[Linux]], [[Microsoft Windows|Windows]], [[macOS]], [[Android (operating system)|Android]], [[iPhone]], [[BlackBerry]]
| {{open source|[[GNU General Public License|GPL-3.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]]
| [[Speex]], [[Opus (audio format)|Opus]], [[G711]], [[GSM]], [[G.722]], [[VP8]] (WebM), [[H263]], [[MPEG4]], [[Theora]] and [[H264]] (plugin)
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| {{Unk}}
| Video, IM, STUN, IPv6 (disables IPv4 support when enabled), P2P, Secure Encryption, User own Encryption via Provided API https://gitlab.linphone.org/BC/public/linphone-desktop
| 4.2.5; {{Start date and age|2020|06|25}}, provides daily snapshots via http://www.linphone.org/snapshots
|-
!{{rh}}| [[Messages (Apple)|Messages]]
| [[macOS]]
| {{proprietary}}
| {{free}}, only [[macOS]] and [[iOS]]
| [[Session Initiation Protocol|SIP]] [[AOL Instant Messenger|AIM]] [[ICQ]] [[Extensible Messaging and Presence Protocol|XMPP]]
| [[H263]], [[H264]]
| {{Unk}}
| {{Unk}}
| Integrated, PBX independent
| 7.0; {{Start date and age|2012|07|25}}
|-
!{{rh}}| MicroSIP
| [[Microsoft Windows|Windows]]
| {{open source|[[GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[STUN]], [[Interactive Connectivity Establishment|ICE]], [[SIMPLE (instant messaging protocol)|SIMPLE]]
| [[Speex]], [[iLBC]], [[GSM]], [[G.711]], [[G.722]], [[G.729]], [[SILK]], [[Linear PCM]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| {{Unk}}
| Video, voice, IM and Presence
| {{Latest stable software release/MicroSIP}}
|-
!{{rh}}| [[Movim]]
| Any, [[Progressive web application]]
| {{open source|[[GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[XMPP]], [[STUN]], [[TURN]]
| Depending the web-browser
| {{Yes|[[Transport Layer Security|TLS]]}}
| 2
| IM, microblogging, social-network, OMEMO encryption, screen-sharing, file transfer
| {{wikidata|qualifier|raw|preferred|single|Q3326936|P348|P548=Q2804309|P577}}
|-
!{{rh}}| [[Mumble (software)|Mumble]]
| [[Linux]], [[macOS]], [[iOS]], [[Microsoft Windows|Windows]], [[Android (operating system)|Android]]
| {{open source|[[New BSD license]]}}
| {{free}}
| [[Interactive Connectivity Establishment|ICE]]
| [[CELT]], [[Speex]], [[Opus (audio codec)|Opus]]
| {{Yes|[[Transport Layer Security|TLS]] and [[OCB mode|OCB-AES128]]}}
| No limit (limited only by server bandwidth and memory)
|Chat with (limited) embedded HTML, [[Automatic Gain Control]], very low [[Latency (audio)|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
| 1.4.287; {{Start date and age|2022|09|14}}
|-
!{{rh}}| [[Nymgo]]
| [[Microsoft Windows|Windows]], [[Android (operating system)|Android]], [[iOS]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]] and [[RTP Control Protocol|RTCP]]
| {{Unk}}
| {{Yes}}
| No limit
|Address Book integration, Call recording/export, Mute, On Hold, Caller ID definition
| 4.2.9; {{Start date and age|2013|03}}
|-
!{{rh}}| [[Phoner]]
| [[Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Telephony Application Programming Interface|TAPI]], [[Common ISDN Application Programming Interface|CAPI]]
| [[G.711]]a, [[G.711]]u, [[G.722]], [[G.726]], [[G.729]], [[GSM]], [[iLBC]], [[speex]], [[Opus (audio codec)|Opus]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| 8
| Conferencing, call redirection, call recording
| {{Latest stable software release/Phoner}}
|-
!{{rh}}| [[PhonerLite]]
| [[Microsoft Windows|Windows]]
| {{proprietary}}
| {{free}}
| [[Session Initiation Protocol|SIP]]
| [[G.711]]a, [[G.711]]u, [[G.722]], [[G.726]], [[G.729]], [[GSM]], [[iLBC]], [[speex]], [[Opus (audio codec)|Opus]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| 8
| Conferencing, call redirection, call recording
| {{Latest stable software release/PhonerLite}}
|-
!{{rh}}| [[Roger Wilco (software)|Roger Wilco GameSpy]]
| [[Microsoft Windows|Windows]]
| {{proprietary}}
| {{dunno}}
| Proprietary
| {{dunno}}
| {{dunno}}
| {{Unk}}
| {{dunno}}
| {{Start date and age|2001}}
|-
!{{rh}}| [[Signal (messaging app)|Signal]]
| [[Linux]], [[macOS]], [[Microsoft Windows|Windows]], [[Android (operating system)|Android]], [[iPhone]]
| {{open source|[[GPLv3]] clients and [[AGPLv3]] server}}
| {{free}}
|RingRTC ([[WebRTC]] over [[Signal Protocol|Signal protocol]]<ref name=":0">{{Cite web|url=https://signal.org/blog/signal-video-calls-beta/|title=Video calls for Signal now in public beta|date=2017-03-13|website=Signal|access-date=2020-03-02}}</ref>)
|[[Opus (audio format)|Opus]]<ref name=":0" />
| {{Yes|[[Transport Layer Security|TLS]], [[Signal Protocol]]<ref name="signal-video-calls-beta"/>}}
| 50<ref name="Signal group">{{cite web |title=Group Calling - Voice or Video |website=Signal Support |url=https://support.signal.org/hc/en-us/articles/360052977792-Group-Calling-Voice-or-Video |access-date=18 December 2024}}</ref>
| Signal also allows users to send text messages, files, voice notes, pictures, GIFs, and video messages over a Wi-Fi or data connection to other Signal users on iOS, Android and a desktop app. The app also supports group messaging, read receipts and typing indicators, both of which can be disabled.
| {{Multiple releases
  | branch1 = Android
  | version1 = {{wikidata|property|preferred|references|edit|Q19718090|P348|P400=Q94|P548=Q2804309}}
  | date1 = {{wikidata|qualifier|preferred|single|Q19718090|P348|P400=Q94|P548=Q2804309|P577}}
  | branch2 = iOS
  | version2 = {{wikidata|property|preferred|references|edit|Q19718090|P348|P400=Q48493|P548=Q2804309}}
  | date2 = {{wikidata|qualifier|preferred|single|Q19718090|P348|P400=Q48493|P548=Q2804309|P577}}
  | branch3 = Desktop
  | version3 = {{wikidata|property|preferred|references|edit|Q19718090|P348|P400=Q16338|P548=Q2804309}}
  | date3 = {{wikidata|qualifier|preferred|single|Q19718090|P348|P400=Q16338|P548=Q2804309|P577}}
}}
|-
!{{rh}}| [[Skype]]
| [[Linux]](with limited functionality),<ref>{{Cite web|url=http://opensourceforu.com/2017/06/microsoft-retire-skype-linux-app-july-1/|title = Microsoft to retire Skype Linux app on July 1|date = 9 June 2017}}</ref> [[macOS]], [[Microsoft Windows|Windows]] 2000-XP-Vista-7-[[Windows Mobile|Mobile]] (unsupported<!--https://support.skype.com/faq/fa10411/Why-can-t-I-download-Skype-Lite-or-Skype-for-Windows-phones-->), [[Binary Runtime Environment for Wireless|BREW]], [[Windows Phone]], [[Android (operating system)|Android]], [[iPhone]], [[PlayStation Portable|PSP]]
| {{proprietary}}
| {{free}}
| Proprietary P2P protocol {{efn|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<ref name="skypesip">{{cite web|title=Skype Connect...|url=http://www.skype.com/en/features/skype-connect/|website=skype.com|publisher=Microsoft Corporation Inc.|access-date=15 November 2014|archive-url=https://web.archive.org/web/20141111022420/http://www.skype.com/en/features/skype-connect/|archive-date=2014-11-11}}</ref>}}
| [[SILK]]
| {{Yes|[[Transport Layer Security|TLS]]}}
| 25 starting with version 3.6.0.216. 10 with 2.x
| Conferencing, video, file transfer, voicemail, Skype to phone, phone to Skype, additional P2P extensions (games, whiteboard, etc...); depending on platform.<!-- E.g. no video and P2P on Windows Mobile -->
| {{Latest stable software release/Skype}}
|-
![[Steam Chat]]
|Web, Phones, Desktop
| {{proprietary}}
|
|WebRTC
|
|
|
|
|
|-
!{{rh}}| [[TeamSpeak]]
| [[Linux]], [[Microsoft Windows|Windows]], [[macOS]], [[FreeBSD]], [[Android (operating system)|Android]], [[iOS]]
| {{proprietary}}
| {{free}}
| {{Unk}}
| [[CELT]], [[Speex]] (both until server version 3.5.0), [[Opus (audio format)|Opus]]<ref>{{cite web|url=http://www.teamspeak.com/?page=newsarchive&ident=20130304 |title=New TeamSpeak3 Client and Server released today |publisher=TeamSpeak Systems GmbH |access-date=2015-08-04}}</ref>
| {{Yes}}
| 32 unlicensed, 512 with Non-Profit License (available until September 2018), up to 1024 (Gamer 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
| 3.5.5; {{Start date and age|2020|11|04}}
|-
!{{rh}}| [[TeamTalk]]
| [[Linux]], [[Microsoft Windows|Windows]], [[macOS]], [[Android (operating system)|Android]], [[iOS]], [[Raspbian]]
| {{proprietary}}
| {{free}}
| {{proprietary}}
| [[Opus (audio format)|Opus]], [[Speex]], [[VP8]]
| {{No}}
| 1000
| Video, file sharing, desktop sharing, stream media files ([[MP3]], [[Audio Video Interleave|AVI]])
| 5.3.3; {{Start date and age|2018|11}}
|-
!{{rh}}| [[TeamViewer]]
| [[Linux]], [[Microsoft Windows|Windows]], [[macOS]], iOS, Android<ref>{{cite web|title=TeamViewer overview|url=http://www.getapp.com/teamviewer-application#overview|publisher=GetApp}}</ref>
| {{proprietary}}
| {{free}} (personal use only)
| {{Unk}}
| {{Unk}}
| {{Yes|[[AES256]]}}
| {{Unk}}
| {{Unk}}
| {{Latest stable software release/TeamViewer}}
|-
!{{rh}}| [[Telephone (application)|Telephone]]
| [[macOS]] 10.10.2
| {{open source|[[BSD licenses|BSD]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[STUN]], [[Interactive Connectivity Establishment|ICE]]
| {{Unk}}
| {{No}}
| {{Unk}}
| Address Book integration
| 1.1.4; {{Start date and age|2012|03|06}}
|-
!{{rh}}| [[Tuenti]]
| [[Android (operating system)|Android]], [[iPhone]], [[Windows Phone]]
| {{proprietary}}
| {{free}}
| [[WebRTC]], [[Session Initiation Protocol|SIP]], [[Extensible Messaging and Presence Protocol|XMPP]]
| [[Internet Low Bitrate Codec|iLBC]], [[Opus (audio codec)|Opus]]
| Yes
| {{Unk}}
| Voice, video, [[Instant messaging]], group chat, photo and video sharing, SMS and MMS, native and social network contacts integration, incoming call/IM push notifications.
| 
|-
!{{rh}}| [[Twinkle (software)|Twinkle]]
| [[Linux]]
| {{open source|[[GNU General Public License|GPL-2.0-or-later]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]]
| [[G.711]] A-law μ-law, [[G.726]], [[GSM 06.10|GSM]], [[iLBC]], [[Speex]] narrow wide ultrawide
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| 3
| Conferencing, chat, file transfer, Firefox integration, call redirection, voicemail, support of VoIP-to-Phone services
| {{Latest stable software release/Twinkle}}
|-
!{{rh}}| [[Ventrilo]]
| [[macOS]], [[Microsoft Windows|Windows]], [[iOS]], [[Android (operating system)|Android]]
| {{proprietary}}
| {{free}}
| {{Unk}}
| {{Unk}}
| {{No}}
| 8
| Conferencing, chat, [[text-to-speech]]
| 3.0.8
|-
!{{rh}}| [[Viber]]
| [[Linux]],{{efn|name=viber-desktop-restriction|Viber must be first installed on a mobile phone to function on a desktop operating system<ref name=viber-desktop-restriction-2>{{cite web|last1=Brad Chacos|first1=Brad|title=Hands on with Viber's new desktop app: It's no Skype|url=http://www.pcworld.com/article/2038073/hands-on-with-vibers-new-desktop-app-its-no-skype.html|website=www.pcworld.com|publisher=IDG Consumer & SMB|access-date=15 November 2014|archive-url=https://web.archive.org/web/20140725080804/http://www.pcworld.com/article/2038073/hands-on-with-vibers-new-desktop-app-its-no-skype.html|archive-date=2014-07-25|quote=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.}}</ref><ref>[https://blogs.wsj.com/digits/2013/05/07/viber-unveils-desktop-app/ Viber Unveils Desktop App]</ref>}} [[macOS]],{{efn|name=viber-desktop-restriction}} [[Microsoft Windows|Windows]],{{efn|name=viber-desktop-restriction}} [[Android (operating system)|Android]], [[Bada (operating system)|Bada]], [[BlackBerry OS]], [[iOS]], [[Series 40]], [[Symbian]], [[Windows Phone]]
| {{proprietary}}
| {{dunno}}
| {{Unk}}
| {{Unk}}
| {{Yes}}<ref name="Lunden-19-April-2016"/>
| {{Unk}}
| Varies by platform: Text, picture and video messaging on all, voice calling only on iPhone, Android and Microsoft's Windows Phone
| {{Latest stable software release/Viber}}
|-
!{{rh}}| [[Wire (software)|Wire]]
| Linux, Windows, macOS, iOS, Android, Web
| {{open source|GPLv3}}
|not free
| {{dunno}}
| Audio: [[Opus (audio format)|Opus]]
Video: [[VP8]]
| {{yes|[[Datagram Transport Layer Security|DTLS]], [[Secure Real-time Transport Protocol|SRTP]]<ref name="Wire Security Whitepaper"/>}}
| 10<ref>{{Cite news|url=https://twitter.com/wire/status/808392988665712644|title=Wire on Twitter|work=Twitter|access-date=2017-02-28|language=en}}</ref>
| 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)
| {{dunno}}
|-
!{{rh}}| [[Yate (telephony engine)|Yate Client]]
| [[Linux]], [[macOS]], [[Microsoft Windows|Windows]]
| {{open source|[[GNU General Public License|GPL]]}}
| {{free}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], [[Extensible Messaging and Presence Protocol|XMPP]], [[H.323]]
| [[G.711]]a, [[G.711]]u, [[GSM 06.10]], [[iLBC]], [[Speex]], [[G.723]], [[G.726]], [[G.728]], [[G.729]]
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]], maybe [[ZRTP]]?}}
| {{Unk}}
| <!-- abilities -->
| 6.0.0; {{Start date and age|2017|09}}
|-
!{{rh}}| [[Zfone]]
| [[Linux]], [[macOS]], [[Microsoft Windows|Windows]]
| {{proprietary}} (with viewable source)
| {{free|Includes time bomb provision}}
| [[Session Initiation Protocol|SIP]], [[Real-time Transport Protocol|RTP]]
| {{Unk}}
| {{Yes|[[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| {{Unk}}
| <!-- abilities -->
| [[Development stage#Beta|Beta]] 2008-09-04 ([[Linux]] 0.9.224), ([[macOS]] 0.9.246), ([[Microsoft Windows|Windows]] 0.9.206)
|-
|}

{{notelist|close}}

== Mobile phones ==
For [[mobile VoIP]] clients:
{|class="wikitable sortable sort-under"
|-
! Program
! [[Operating system]]s
! [[Software license|License]]
! [[Open-source software|Open source]]
! [[Communications protocol|Protocols]]
! [[Codec]]s
! [[Encryption]]
! Other abilities
! Latest release
|-
| [[Jami (software)|Jami]]
| [[iOS]], [[Android (operating system)|Android]]<ref>[https://jami.net/download/] Jami downloads</ref>
| {{open source|[[GNU General Public License|GPLv3]]}} 
| {{Yes}}
| [[Session Initiation Protocol|SIP]] 
| Video: H264, VP8, MP4V, H263, Audio: [[Opus (audio format)|Opus]] 48000 hz, G722 PCMA, PCMU 
| {{yes|[[Secure Real-time Transport Protocol|SRTP]], SIP over [[Transport Layer Security|TLS]] }}
| {{dunno}}
| Version 202103261733 {{Start date and age|2021|03}}
|-
| [[Line (application)|Line]]
| Android, iOS
| {{proprietary}}
| {{No}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| 
|-
| [[Signal (messaging app)|Signal]]
| iOS, Android
| {{open source|[[GNU General Public License|GPLv3]]}}
| {{Yes}}
| [[WebRTC]]<ref name="signal-video-calls-beta">{{cite web|last1=Marlinspike|first1=Moxie|title=Video calls for Signal now in public beta|url=https://whispersystems.org/blog/signal-video-calls-beta/|publisher=Open Whisper Systems|access-date=22 March 2017|date=14 February 2017}}</ref>
| [[Opus (audio format)|Opus]]<ref name="signal-video-calls-beta"/>
| {{Yes|[[Transport Layer Security|TLS]], [[Signal Protocol]]<ref name="signal-video-calls-beta"/>}}
| End-to-end encryption by default for everything. CallKit and location privacy,<ref name="signal-video-calls">{{cite web|last1=Marlinspike|first1=Moxie|title=Video calls for Signal out of beta|url=https://whispersystems.org/blog/signal-video-calls/|publisher=Open Whisper Systems|access-date=22 March 2017|date=13 March 2017}}</ref> one-to-one and group messaging, video calling,<ref name="signal-video-calls"/> image/video sharing, timed messages, identity verification, screenshot blocking. Android only: SMS/MMS messaging, doodling,<ref name="doodles-stickers-censorship">{{cite web|last1=Marlinspike|first1=Moxie|title=Doodles, stickers, and censorship circumvention for Signal Android|url=https://whispersystems.org/blog/doodles-stickers-censorship/|publisher=Open Whisper Systems|access-date=22 March 2017|date=21 December 2016}}</ref> GIF sharing.<ref name="giphy-experiment">{{cite web|last1=Marlinspike|first1=Moxie|title=Signal and GIPHY|url=https://whispersystems.org/blog/giphy-experiment/|publisher=Open Whisper Systems|access-date=22 March 2017|date=1 November 2016}}</ref>
| Android	5.2.3 / 15 September 2023
iOS	6.41.1 / 15 September 2023
Desktop	1.33.4 / 13 September 2023
|-
| [[Sipdroid]]
| [[Android (operating system)|Android]]
| {{open source|[[GNU General Public License|GPL]]}}
| {{Yes}}
| [[Session Initiation Protocol|SIP]]
| {{dunno}}
| {{dunno}}
| Uses [[Wi-Fi]], [[3G]] or [[Enhanced Data Rates for GSM Evolution|EDGE]]
| 2.7
|-
| [[Tango (application)|Tango]]
| iOS, Android, Microsoft Windows, macOS, Windows Phone
| {{proprietary}}, [[freeware]]
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| VoIP, Wi-Fi out & in, SMS over IP, call-through & call-back, instant messaging, videoconferencing
| {{dunno}}
|-
| [[WhatsApp]]
|
Android, BlackBerry, iOS, Symbian, Windows Phone
| {{proprietary}}, [[freeware]]
| {{No}}
| {{dunno}}
| {{dunno}}
| {{yes|[[Elliptic curve Diffie–Hellman|ECDH]], [[Secure Real-time Transport Protocol|SRTP]]}}<ref>{{cite web|title=WhatsApp Encryption Overview&nbsp;– Technical white paper|url=https://www.whatsapp.com/security/WhatsApp-Security-Whitepaper.pdf|publisher=WhatsApp Inc.|access-date=9 April 2016|date=4 April 2016}}</ref>
| VoIP and instant messaging over Wi-Fi or a data connection.
| {{Latest stable software release/WhatsApp}}
|}

== Frameworks and libraries ==
{| class="wikitable sortable sort-under"
|-
! Program
! [[Operating system]]s
! [[Software license|License]]
! [[Communications protocol|Protocols]], based on, compatible with
! [[Encryption]]
! Other abilities
! Key and target markets
! Latest release
|-
| [[Telepathy (software)|Telepathy]], [[Farstream]]
| [[Linux]], [[macOS]], [[Microsoft Windows|Windows]]
| {{open source|[[GNU Lesser General Public License|LGPL]]}}
| SIP, [[Extensible Messaging and Presence Protocol|XMPP]] ([[Jingle (protocol)|Jingle]]), [[Interactive Connectivity Establishment|ICE]] (STUN/TURN), [[Universal Plug and Play|UPnP]]
| {{No}}
| Multi-user A/V conferencing, IM, collaborative applications
| Mobile devices (Maemo, Meego), Linux desktop or embedded
| spec 0.27.2; {{Start date and age|2013|9|24}}
|-
| [[Open Phone Abstraction Library|OPAL]]
| [[Microsoft Windows|Windows]], [[Linux]] (including embedded variants), [[macOS]]
| {{open source|[[Mozilla Public License|MPL]]}}
| SIP, H.323, IAX2, CAPI, VXML
| {{Unk}}
| Multi-user A/V conferencing, IM, IVR
| Softphones, softswitches, telephony application servers
| 3.14.3; {{Start date and age|2014|10|10}}
|-
| [[OSIP|GNU oSIP]]
| [[Linux]], [[Microsoft Windows|Windows]], [[macOS]], [[Android (operating system)|Android]], [[iPhone]], [[BlackBerry]]
| {{open source|[[GNU Lesser General Public License|LGPL]]}}
| SIP, SDP
| {{Unk}}
| Multi-user A/V conferencing, IM, IVR
| Softphones, embedded and mobile devices, telephony application servers
| 4.1.0; {{Start date and age|2013|12|18}}
|}

== Server software ==
{| class="wikitable sortable sort-under"
|-
! Name
! [[Operating system]]s
! [[Software license|License]]
! [[Communications protocol|Protocols]]
! [[Encryption]]
! Notable features
! Target markets
! [[Software release life cycle|Latest release]]
|-
| [[3CX Phone System]]
| [[Microsoft Windows|Windows]], [[Linux]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Voice over IP|VoIP]]/[[VideoOverIP]] calls and conferencing, [[voicemail]] and [[instant messaging]]
| < 50,000 users
| 18.2; {{Start date and age|2021|12|8}}
|-
| [[AskoziaPBX]]
| [[Standalone program]] ([[Linux]]-based)
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]], [[H.323]], [[Inter-Asterisk eXchange|IAX]], [[Skinny Client Control Protocol|SCCP]]
| {{No}}
| [[Integrated Services Digital Network|ISDN]], [[voicemail]], [[Conference call|conferencing]], [[Music on hold|MOH]], [[Automatic call distributor|ACD]], [[Interactive voice response|IVR]], [[call forwarding]], [[Call-recording software|call recording]]
| [[Small and medium enterprises|SME]]s up to 50 users
| 5.4; {{Start date and age|2017|9|2}}
|-
| [[Asterisk PBX]]
| [[Linux]], [[Berkeley Software Distribution|BSD]], [[macOS]], [[Solaris (operating system)|Solaris]]
| {{Open source|[[GNU General Public License|GPL-2.0+]], optional: [[Proprietary software|Proprietary]]<ref>{{Cite web|title=Licensing|url=https://www.asterisk.org/products/software/licensing/|url-status=live|archive-url=https://web.archive.org/web/20210117002034if_/https://www.asterisk.org/products/software/licensing/|archive-date=2021-01-17|access-date=2022-02-18|website=[[Asterisk PBX|Asterisk]]|language=en-US|df=mdy-all}}</ref>}}
| [[Session Initiation Protocol|SIP]], [[H.323]], [[Inter-Asterisk eXchange|IAX]], [[Media Gateway Control Protocol|MGCP]], [[VoFR]], [[XMPP]], [[Google Talk]], [[Time-division multiplexing|TDM]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Voice over IP|VoIP]] gateway, [[voicemail]], basic accounting (expandable with [[Open Database Connectivity|ODBC]]-compliant database), billing, [[Conference call|conferencing]], [[hot desking]], [[Interactive voice response|IVR]] trees with conditional logic, [[call waiting]], [[Automatic call distributor|automated call distribution]]
| Enthusiasts, developers, enterprise users (capacity dependent on server design, scalable across multiple servers)
| {{Latest stable software release/Asterisk}}
|-
| [[Brekeke PBX]]
| [[Linux]], [[Microsoft Windows|Windows]] [[Windows Server 2016|Server 2016]] and [[Windows Server 2019|Server 2019]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Voice over IP|VoIP]]/[[VideoOverIP]] calls and conferencing, [[voicemail]]
| Hosted service providers, Mid-large enterprise
| 3.12.2.2; {{Start date and age|2022|1|11}}
|-
| [[CommuniGate Pro]]
| [[Linux]], [[Berkeley Software Distribution|BSD]], [[macOS]], [[Microsoft Windows|Windows]], [[Solaris (operating system)|Solaris]], [[HP-UX]], [[IBM AIX|AIX]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]], [[XIMSS]], [[XMPP]], [[WebRTC]]
| {{Yes|[[Secure Sockets Layer|SSL]], [[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Session Initiation Protocol|SIP]] Registrar/Proxy, Authentication, [[Diameter (protocol)|Diameter]], [[RADIUS]], [[Telephone number mapping|ENUM]]
| [[Mobile network operator]]s, [[Internet service provider|ISPs]], [[Software as a service|SaaS]] providers
| 6.2.14; {{Start date and age|2019|08|16}}
|-
| [[Dial Gate VoIP Softswitch]]
| [[Linux]], [[Microsoft Windows|Windows]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Billing server, real-time account and line monitoring, [[web portal]]
| [[Softswitch]] users, service providers
| 4.3; {{Start date and age|2014|06|01}}
|-
| [[Dial-Office IP-PBX]]
| [[Linux]], [[Microsoft Windows|Windows]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Unified communications, [[conference call]]s, remote worker support and [[voicemail]]
| Small businesses, Mid-large enterprises
| 4.1; {{Start date and age|2013|12}}
|-
| [[Elastix]]
| [[Linux]]
| {{Proprietary}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], [[H.323]], [[XMPP]]
| {{Yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Unified communication server that also supports chat, mail and fax.
| Capacity dependent on server design, scalable across multiple servers
| 5.0.0; {{Start date and age|2016|12|07}}
|-
| [[FreeSWITCH]]
| [[Linux]], [[Berkeley Software Distribution|BSD]], [[macOS]], [[Solaris (operating system)|Solaris]], [[Microsoft Windows|Windows]]
| {{open source|[[Mozilla Public License]]}}
| [[Session Initiation Protocol|SIP]], [[NAT-PMP]], [[STUN]], [[SIMPLE (instant messaging protocol)|SIMPLE]], [[Extensible Messaging and Presence Protocol|XMPP]], [[Google Talk]] ([[Jingle (protocol)|Jingle]]), [[Inter-Asterisk eXchange|IAX]], [[H.323]], [[Media Resource Control Protocol|MRCP]], [[RSS]]<!-- Which one? Does this refer to "Really Simple Syndication", "Rich Site Summary", or any other out of the long list available at http://en.wikipedia.org/wiki/RSS_%28disambiguation%29 ? -->, [[Skype]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]], [[ZRTP]]}}
| Recording, Voicemail, Conferencing, [[RADIUS]], [[Telephone number mapping|ENUM]], IM Proxy, Streaming, Media gateway, Soft-PBX, IVR (modular)
| Large soft-switch users, home [[Private branch exchange|PBX]] users, softphone users
| {{Latest stable software release/FreeSWITCH}}
|-
| [[FreePBX]]
| [[Linux]], [[Berkeley Software Distribution|BSD]], [[Solaris (operating system)|Solaris]]
| {{open source|[[GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], [[H.323]], [[XMPP]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Complete PABX Service, based on [[Asterisk PBX|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; {{Start date and age|2017|8|}}
|-
| [[Galene (software)|Galene]]
| [[Linux]], [[Unix]], [[Mac OS]], [[Windows]]
| {{open source|[[MIT Licence]]}}
| [[WebRTC]], WHIP
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Lightweight, efficient, easy to install and to administer
| Teaching, conferences, meetings
| 0.96.2; {{Start date and age|2025|1|}}
|-
| [[GNU Gatekeeper]]
| [[Linux]], [[FreeBSD]], [[macOS]], [[Microsoft Windows|Windows]] XP-2000-Vista-7
| {{open source|[[GNU General Public License|GPL]]}}
| [[H.323]]
| {{Yes|[[H.235]]}}
| H.460.18 firewall traversal, routing, accounting
| video conferencing, VoIP carriers large and small
| 3.7; {{Start date and age|2014|08|15}}
|-
| [[HERO Hosted PBX]]
| [[Linux]], [[Microsoft Windows|Windows]]
| {{proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Unified Communications, billing server, cloud-based management and web interface
| Mid-large enterprises, VoIP carriers and service providers, telecom operators
| 4.3; {{Start date and age|2013|12}}
|-
| [[Mumble (software)|Murmur]]
| [[Linux]], [[Berkeley Software Distribution|BSD]], [[macOS]], [[Microsoft Windows|Windows]]
| {{open source|[[BSD licenses|BSD]], [[GNU General Public License|GPL]]}}
| [[CELT]], [[Speex]], [[Opus (audio codec)|Opus]]
| {{yes|[[Transport Layer Security|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; {{Start date and age|2016|09|24}}
|-
| [[Kamailio]], [[OpenSIPS]] (formerly named OpenSER)
| [[Linux]], [[Berkeley Software Distribution|BSD]], [[Solaris (operating system)|Solaris]]
| {{open source|[[GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]], [[Extensible Messaging and Presence Protocol|XMPP]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| [[Session Initiation Protocol|SIP]] registrar-proxy, authentication, [[Diameter (protocol)|Diameter]], [[RADIUS]], [[Telephone number mapping|ENUM]], least-cost-routing, many others
| SIP Service Providers
| 5.2.8; {{Start date and age|2020|10}}
|-
| [[SIP Express Router (SER)]]
| [[Linux]], [[Berkeley Software Distribution|BSD]], [[Solaris (operating system)|Solaris]]
| {{open source|[[GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]]
| {{no}}
| [[Session Initiation Protocol|SIP]] Registrar/Proxy, Authentication, [[Diameter (protocol)|Diameter]], [[RADIUS]], [[Telephone number mapping|ENUM]], many others
| SIP Service Providers
| 2.0.0 Ottendorf
|-
| [[sipX|sipXecs IP PBX]]
| [[Linux]]
| {{open source|[[GNU Affero General Public License|AGPL]]}}
| Native [[Session Initiation Protocol|SIP]] call control, [[Extensible Messaging and Presence Protocol|XMPP]]
| {{yes|[[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|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; {{Start date and age|2014|07}}
|-
| [[vzRoom]]
| [[Microsoft Windows|Windows]]
| {{proprietary}}
| [[Session Initiation Protocol|SIP]]
| {{yes|[[Secure Sockets Layer|SSL]], [[Transport Layer Security|TLS]], [[Advanced Encryption Standard|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; {{Start date and age|2010|11}}
|-
| [[Yate (telephony engine)|Yate]]
| [[Berkeley Software Distribution|BSD]], [[Linux]], [[macOS]], [[Microsoft Windows|Windows]]
| {{open source|[[GNU General Public License|GPL]]}}
| [[Session Initiation Protocol|SIP]], [[Inter-Asterisk eXchange|IAX]], [[H.323]], [[ISDN]], [[Extensible Messaging and Presence Protocol|XMPP]] (Jabber), [[Jingle (protocol)|Jingle]] ([[Google Talk]]), [[Media Gateway Control Protocol|MGCP]], [[Signalling System No. 7|SS7]] over IP, Cisco SLT (Signalling Link Transport) (SS7 MTP2 backhaul over IP), [[Stream Control Transmission Protocol|SCTP]], [[Skinny Client Control Protocol|SCCP]], [[Transaction Capabilities Application Part|TCAP]], [[Mobile Application Part|MAP]] [[Customised Applications for Mobile networks Enhanced Logic|CAMEL]]
| {{yes|[[Secure Sockets Layer|SSL]], [[Transport Layer Security|TLS]], [[Secure Real-time Transport Protocol|SRTP]]}}
| Voice, video, file transfer, data, H323 to SIP signalling proxy, instant messaging, [[Interactive Voice Response|IVR]], PC2Phone and Phone2PC gateway, SCCP&nbsp;— 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
| 6.3; {{Start date and age|2021|02}}
|}

== Secure VoIP software ==
{{expand section|date=July 2016}}
{{Outdated|part=section|date=November 2024}}

=== VoIP software with client-to-client encryption ===

The following table is an overview of those VoIP clients which (can) provide [[end-to-end encryption]].
{| class="wikitable sortable sort-under" style="font-size: smaller; width: 100%; text-align: center;"
|-
! rowspan=2 | Client name
! rowspan=2 | Development status
! rowspan=2 | [[Open-source software|Open source]] client
! rowspan=2 | End-to-end authentication<ref group=lower-alpha name="end-to-end-authentication">End-to-end authentication protects communications from man-in-the-middle attacks by the service provider.</ref>
! colspan=4 | [[Cryptographic protocol|Encryption protocols]]
! rowspan=2 | [[Forward secrecy]]
! rowspan=2 | Multiple encryption
! rowspan=2 | Encrypted group calling
! rowspan=2 | [[Proxy server|Proxy]], [[Tor (anonymity network)|Tor]]
|-
! [[ZRTP]]
! [[ECDH]]
! [[Datagram Transport Layer Security|DTLS]]
! [[Secure Real-time Transport Protocol|SRTP]]
|-
! [[FaceTime]]
| {{Active}}
| {{no}}<ref name="EFF">{{cite web | url = https://www.eff.org/node/82654 | publisher = Electronic Frontier Foundation | title = Secure Messaging Scorecard. Which apps and tools actually keep your messages safe? | date = 4 November 2014 |access-date=11 July 2016}}</ref>
| {{yes}}<ref name="Apple Platform Security">{{Cite web |title=FaceTime security |url=https://support.apple.com/en-gb/guide/security/seca331c55cd/1/web/1 |access-date=2025-02-08 |website=Apple Support |language=en}}</ref>
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{yes}}<ref name="Apple Platform Security"/>
| {{yes}}
| {{dunno}}
| {{yes}}
| {{no}}
|-
! [[Jami (software)|Jami]]
| {{Active}}
| {{yes}}
| {{yes}}
| {{no}}
| {{dunno}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{dunno}}
| {{yes}}
| {{dunno}}
|-
! [[Jitsi]]<ref group=lower-alpha name="sip-encryption">Only if the user has registered with a compatible SIP provider. Some SIP providers do not support certain encryption protocols.</ref>
| {{Active}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{yes}}
| {{no}}
| {{yes}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{yes}}
| {{yes}}
| {{dunno}}
|-
! [[Line (application)|Line]]<ref name="Line-2016-08-10">{{cite web|title="Letter Sealing" End-to-End Encryption Indicator Icon Introduced to LINE Messaging App|url=https://linecorp.com/en/pr/news/en/2016/1464|publisher=Line Corporation|access-date=29 September 2016|date=10 August 2016}}</ref><ref name="Shin-2016-08-11">{{cite web|author1=Shin, Ki Bin|title=The next step for even safer messaging: Letter Sealing|url=http://developers.linecorp.com/blog/?p=3938|publisher=Line Corporation|access-date=30 September 2016|date=11 August 2016|archive-url=https://web.archive.org/web/20161002044533/http://developers.linecorp.com/blog/?p=3938|archive-date=2 October 2016|url-status=dead}}</ref>
| {{Active}}
| {{no}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{no}}<ref name="Line-2016-08-10"/>
| {{no}}
|-
! [[Linphone]]<ref group=lower-alpha name="sip-encryption"/>
| {{Active}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{dunno}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{yes}}
| {{dunno}}
| {{no}}
|-
! [[Signal (messaging app)|Signal]]
| {{Active}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{no}}
| {{yes}}
| {{no}}
| {{yes}}
| {{yes}}<ref name="EFF"/>
| {{yes}}
| {{yes}}
| {{depends}}<ref>{{cite web|last1=Marlinspike|first1=Moxie|title=Video calls for Signal out of beta|url=https://whispersystems.org/blog/signal-video-calls/|publisher=Open Whisper Systems|access-date=30 March 2017|date=13 March 2017}}</ref>
|-
! [[Skype]]<br>(opt-in per conversation,<br>one pair of devices per conversation)<ref>{{cite web |title=What are Skype Private Conversations? |url=https://support.skype.com/en/faq/FA34824/what-are-skype-private-conversations |website=Skype |publisher=Microsoft |access-date=24 May 2020 |quote=Note: Private conversations can only be accessed on one device at a time.}}</ref>
| {{no|Abandonware}}
| {{no}}
| {{yes}}<ref>{{cite web |title=What are Skype Private Conversations? --(private conversations white paper)--> Skype Private Conversation Technical white paper |url=https://support.skype.com/en/faq/FA34824/what-are-skype-private-conversations |publisher=Microsoft |access-date=24 May 2020 |quote=Users can verify the security of their conversations by checking the key setup between two users.}}</ref>
| {{no}}
| {{no}}
| {{no}}
| {{yes}}<ref>{{cite web |title=What are Skype Private Conversations? --(private conversations white paper)--> Skype Private Conversation Technical white paper |url=https://support.skype.com/en/faq/FA34824/what-are-skype-private-conversations |publisher=Microsoft |access-date=24 May 2020 |quote=Caller encrypts the SRTP using the generated encryption key, which can only be decrypted by the callee. After the call is setup, the media packets are encrypted using the SRTP keys.}}</ref>
| {{dunno}}
| {{dunno}}
| {{no}}
| {{no}}
|-
! [[Telegram (messaging service)|Telegram]]
| {{Active}}
| {{yes}}
| {{yes}}<ref>{{cite web|title=Voice Calls: Secure, Crystal-Clear, AI-Powered|url=https://telegram.org/blog/calls|publisher=Telegram|access-date=30 March 2017|date=30 March 2017}}</ref>
| {{no}}
| {{no}}
| {{no}}
| {{no}}
| {{yes}}
| {{dunno}}
| {{no}}
| {{no}}
|-
! [[Threema]]
| {{Active}}
| {{partial|Partially}}<ref group=lower-alpha name="encryption-open" /><ref>{{cite web|title=Where can I find Threema's source code?|url=https://threema.ch/en/faq/source_code|website=threema.ch|publisher=Threema|access-date=30 October 2017|date=n.d.}}</ref>
| {{yes}}<ref name="threema-whitepaper">{{cite web|title=Threema cryptography whitepaper|url=https://threema.ch/press-files/2_documentation/cryptography_whitepaper.pdf|website=threema.ch|publisher=Threema|access-date=30 October 2017|date=n.d.}}</ref>
| {{no}}
| {{yes}}<ref name="threema-whitepaper" />
| {{yes}}<ref name="threema-whitepaper" />
| {{yes}}<ref name="threema-whitepaper" />
| {{partial|Partially}}<ref group="lower-alpha" name="threema-forward-secrecy">Only on the network connection, not on the end-to-end layer.</ref><ref name="threema-whitepaper" />
| {{yes}}
| {{no}}
| {{no}}
|-
! [[Viber]]<ref name="Lunden-19-April-2016">{{cite web|last1=Lunden|first1=Ingrid|title=Viber adds end-to-end encryption and hidden chats as the messaging app privacy wave grows|url=https://techcrunch.com/2016/04/19/viber-adds-end-to-end-encryption-hidden-chats-universal-delete-as-messaging-app-privacy-grows/|website=TechCrunch|publisher=AOL Inc.|access-date=12 July 2016|date=19 April 2016}}</ref>
| {{Active}}
| {{no}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{dunno}}
| {{no}}
|-
! [[WhatsApp]]
| {{Active}}
| {{partial|Partially}}<ref group=lower-alpha name="encryption-open">Only the encryption related source code is open.</ref><ref name="whatsapp-ows" />
| {{yes}}<ref name="whatsapp-ows">{{cite web|title=WhatsApp Encryption Overview&nbsp;– Technical white paper|url=https://www.whatsapp.com/security/WhatsApp-Security-Whitepaper.pdf|publisher=WhatsApp Inc.|access-date=5 April 2016|date=4 April 2016}}</ref>
| {{no}}
| {{yes}}<ref name="whatsapp-ows"/>
| {{no}}
| {{yes}}<ref name="whatsapp-ows"/>
| {{yes}}<ref name="whatsapp-ows"/>
| {{yes}}<ref name="whatsapp-ows"/>
| {{yes}}<ref name="whatsapp-ows"/>
| {{no}}
|-
! [[Wire (software)|Wire]]
| {{Active}}
| {{yes}}
| {{yes}}<ref>{{cite web|title=A major upgrade to calling|website=Medium|publisher=Wire Swiss GmbH|url=https://medium.com/wire-news/a-major-upgrade-to-calling-9ac8780741a1#.5jt0cku16|date=14 March 2017|access-date=14 March 2017}}</ref>
| {{no}}
| {{dunno}}
| {{yes}}<ref name="Wire Security Whitepaper">{{Cite web|url=https://wire.com/resource/Wire%20Security%20Whitepaper/download/|title=Wire Security Whitepaper|publisher=Wire Swiss GmbH|access-date=13 April 2016}}{{Dead link|date=November 2019 |bot=InternetArchiveBot |fix-attempted=yes }}</ref>
| {{yes}}<ref name="Wire Security Whitepaper"/>
| {{yes}}<ref>{{cite web |title=Security & Privacy |url=https://wire.com/en/security/ |website=Wire |access-date=19 January 2020 |quote=New encryption keys are used for each message, so a compromised key has minimal impact.}}</ref>
| {{yes}}
| {{yes}}
| {{no}}
|-
! [[Zfone]]
| {{no|Abandonware}}
| {{yes|Viewable source}}<ref>{{cite web|url=http://zfoneproject.com/faq.html#opensource|title=Is Zfone open source?|website=zfoneproject.com|publisher=Zfone|access-date=26 August 2016|date=2006}}</ref>
| {{yes}}
| {{yes}}
| {{optional}}<ref>{{cite web|url=http://zfoneproject.com/faq.html#suiteb|title=Do you support Elliptic Curve Diffie-Hellman?|website=zfoneproject.com|publisher=Zfone|access-date=26 August 2016|date=2006}}</ref>
| {{dunno}}
| {{yes}}<ref>{{cite web|url=http://zfoneproject.com/faq.html#srtp|title=Why do we need ZRTP if we already have SRTP? Isn't SRTP good enough?|website=zfoneproject.com|publisher=Zfone|access-date=26 August 2016|date=2006}}</ref>
| {{yes}}
| {{yes}}
| {{dunno}}
| {{dunno}}
|-
|}

== See also ==
* [[Comparison of audio coding formats]]
* [[Comparison of cross-platform instant messaging clients]]
* [[Comparison of web conferencing software]]
* [[List of codecs]]
* [[List of SIP software]]
* [[List of video telecommunication services and product brands]]
* [[Matrix (protocol)]]
* [[Secure communication]]
* [[Comparison of user features of messaging platforms]]

== Notes ==
<references group="lower-alpha" />
== References ==
{{Reflist|30em}}

{{Telecommunications}}

{{DEFAULTSORT:Comparison Of Voip Software}}
[[Category:VoIP software]]
[[Category:Cryptographic software]]
[[Category:Network software comparisons|VoIP software]]
[[Category:Online services comparisons|VoIP software]]