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. [1] 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 supports 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 Desktop applications.
Program | Operating systems | License | Costs | Protocols | Codecs | Encryption | Max conference peers | Other abilities | Latest release | ||||||||||||
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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 [2] | No limit | IM, file transfer, desktop sharing, multi-party conference, wideband | Blink Qt | ||||||||||||
Battle.net | macOS, Android, iOS, Windows | Proprietary | Free | Unknown | Unknown | Unknown | Unknown | IM, multi-party conference | Unknown | ||||||||||||
Discord | macOS, Android, iOS, Windows, Linux | Proprietary | Free, Premium "Nitro" Subscription for Additional Features. | RTP, UDP, WS, HTTPS | Opus | TLS | 5000 soft limit for voice calls, [3] 25 hard limit for video [4] | IM, file sharing, in-game overlay | 59746; April 24, 2020 | ||||||||||||
Eyeball Chat | Windows | Proprietary | Free | SIP, STUN, ICE, XMPP | Unknown | Yes | 5 [5] | IM, Conferencing, Voice, Video and SIMPLE based presence | Windows 3.2; 2009 | ||||||||||||
FaceTime | iOS, macOS | Proprietary | Free | SIP, IETF, Signaling protocol for VoIP, STUN, TURN and ICE| IETF, technologies for traversing firewalls and NAT | H.264 Video, AAC-ELD Audio, H.263 and VP8 | RTP, SRTP IETF|standards for delivering real-time and encrypted media streams for VoIP. | 20 | Video, voice, conferencing, with additional tools available as "Services". | |||||||||||||
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 [6] | 8.5.2; May 8, 2011 | ||||||||||||
Jami | Android, FreeBSD, iOS, iPhone, Linux, Microsoft Windows, OS X [7] | GPL-3.0-or-later | 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 |
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Jitsi | Linux, macOS, Windows (all java supported). Experimental Android builds are also available. [12] | Apache-2.0 | 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, [13] P2P not supported [14] ), call recording, 64-bit | 2.10 (build.5550) (February 5, 2017) [±] | ||||||||||||
Linphone | Linux, Windows, macOS, Android, iPhone, BlackBerry | GPL-3.0-or-later | 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, Secure Encryption, User own Encryption via Provided API https://gitlab.linphone.org/BC/public/linphone-desktop | 4.2.5; June 25, 2020 , provides daily snapshots via http://www.linphone.org/snapshots | ||||||||||||
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-2.0-or-later | 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 | 3.20.7 (25 August 2021) [±] [15] | ||||||||||||
Movim | Any, Progressive web application | GPL-2.0-or-later | Free | XMPP, STUN, TURN | Depending the web-browser | TLS | 2 | IM, microblogging, social-network, OMEMO encryption, screen-sharing, file transfer | 2024-09-24 | ||||||||||||
Mumble | Linux, macOS, iOS, Windows, Android | New BSD license | Free | ICE | CELT, Speex, Opus | TLS and OCB-AES128 | No limit (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 | 1.4.287; September 14, 2022 | ||||||||||||
Nymgo | Windows, Android, iOS | Proprietary | Free | SIP, RTP and RTCP | Unknown | Yes | No limit | 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 | 3.23 (5 March 2021) [±] [16] | ||||||||||||
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 | 3.27 (11 November 2024) [±] [17] | ||||||||||||
Roger Wilco GameSpy | Windows | Proprietary | ? | Proprietary | ? | ? | Unknown | ? | 2001 | ||||||||||||
Signal | Linux, macOS, Windows, Android, iPhone | GPLv3 clients and AGPLv3 server | Free | RingRTC (WebRTC over Signal protocol [18] ) | Opus [18] | ? | Unknown | 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. |
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Skype | Linux(with limited functionality), [22] 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 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. |
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Steam Chat | Web, Phones, Desktop | Proprietary | WebRTC | ||||||||||||||||||
TeamSpeak | Linux, Windows, macOS, FreeBSD, Android, iOS | Proprietary | Free | Unknown | CELT, Speex (both until server version 3.5.0), Opus [31] | 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; November 4, 2020 | ||||||||||||
TeamTalk | Linux, Windows, macOS, Android, iOS, Raspbian | Proprietary | Free | Proprietary | Opus, Speex, VP8 | No | 1000 | Video, file sharing, desktop sharing, stream media files (MP3, AVI) | 5.3.3; November 2018 | ||||||||||||
TeamViewer | Linux, Windows, macOS, iOS, Android [32] | Proprietary | Free (personal use only) | Unknown | Unknown | AES256 | Unknown | Unknown |
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Telephone | macOS 10.10.2 | BSD | Free | SIP, STUN, ICE | Unknown | No | Unknown | Address Book integration | 1.1.4; March 6, 2012 | ||||||||||||
Tuenti | Android, iPhone, Windows Phone | Proprietary | Free | WebRTC, SIP, XMPP | iLBC, Opus | Yes | Unknown | 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-2.0-or-later | 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 | 1.10.3 (February 19, 2022) [±] | ||||||||||||
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 [44] | Unknown | Varies by platform: Text, picture and video messaging on all, voice calling only on iPhone, Android and Microsoft's Windows Phone |
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Wire | Linux, Windows, macOS, iOS, Android, Web | GPLv3 | not free | ? | Audio: Opus Video: VP8 | DTLS, SRTP [49] | 10 [50] | 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) | ? | ||||||||||||
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 | Proprietary (with 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) | |||||||||||||
For mobile VoIP clients:
Program | Operating systems | License | Open source | Protocols | Codecs | Encryption | Other abilities | Latest release | ||||||||
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Jami | iOS, Android [51] | GPLv3 | Yes | SIP | Video: H264, VP8, MP4V, H263, Audio: Opus 48000 hz, G722 PCMA, PCMU | SRTP, SIP over TLS | ? | Version 202103261733 March 2021 | ||||||||
Line | Android, iOS | Proprietary | No | ? | ? | ? | ? | |||||||||
Signal | iOS, Android | GPLv3 | Yes | WebRTC [52] | Opus [52] | TLS, Signal Protocol [52] | End-to-end encryption by default for everything. CallKit and location privacy, [53] one-to-one and group messaging, video calling, [53] image/video sharing, timed messages, identity verification, screenshot blocking. Android only: SMS/MMS messaging, doodling, [54] GIF sharing. [55] | Android 5.2.3 / 15 September 2023 iOS 6.41.1 / 15 September 2023 Desktop 1.33.4 / 13 September 2023 | ||||||||
Sipdroid | Android | GPL | Yes | SIP | ? | ? | Uses Wi-Fi, 3G or EDGE | 2.7 | ||||||||
Tango | iOS, Android, Microsoft Windows, macOS, Windows Phone | Proprietary, freeware | ? | ? | ? | ? | VoIP, Wi-Fi out & in, SMS over IP, call-through & call-back, instant messaging, videoconferencing | ? | ||||||||
Android, BlackBerry, iOS, Symbian, Windows Phone | Proprietary, freeware | No | ? | ? | ECDH, SRTP [56] | VoIP and instant messaging over Wi-Fi or a data connection. |
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Program | Operating systems | License | Protocols, based on, compatible with | Encryption | Other abilities | Key and target markets | Latest release |
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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 |
Name | Operating systems | License | Protocols | Encryption | Notable features | Target markets | Latest release |
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3CX Phone System | Windows, Linux | Proprietary | SIP | TLS, SRTP | VoIP/VideoOverIP calls and conferencing, voicemail and instant messaging | < 50,000 users | 18.2; December 8, 2021 |
AskoziaPBX | Standalone program (Linux-based) | Proprietary | SIP, H.323, IAX, SCCP | No | ISDN, voicemail, conferencing, MOH, ACD, IVR, call forwarding, call recording | SMEs up to 50 users | 5.4; September 2, 2017 |
Asterisk PBX | Linux, BSD, macOS, Solaris | GPL-2.0+, optional: Proprietary [61] | SIP, H.323, IAX, MGCP, VoFR, XMPP, Google Talk, TDM | TLS, SRTP | VoIP gateway, voicemail, basic accounting (expandable with ODBC-compliant database), billing, conferencing, hot desking, IVR trees with conditional logic, call waiting, automated call distribution | Enthusiasts, developers, enterprise users (capacity dependent on server design, scalable across multiple servers) | 21.3.1 (17 May 2024 [62] ) 20.5.0 LTS (18 October 2023 [63] ) |
Brekeke PBX | Linux, Windows Server 2016 and Server 2019 | Proprietary | SIP | TLS, SRTP | VoIP/VideoOverIP calls and conferencing, voicemail | Hosted service providers, Mid-large enterprise | 3.12.2.2; January 11, 2022 |
CommuniGate Pro | Linux, BSD, macOS, Windows, Solaris, HP-UX, AIX | Proprietary | SIP, XIMSS, XMPP, WebRTC | SSL, TLS, SRTP | SIP Registrar/Proxy, Authentication, Diameter, RADIUS, ENUM | Mobile network operators, ISPs, SaaS providers | 6.2.14; August 16, 2019 |
Dial Gate VoIP Softswitch | Linux, Windows | Proprietary | SIP | TLS, SRTP | Billing server, real-time account and line monitoring, web portal | Softswitch users, service providers | 4.3; June 1, 2014 |
Dial-Office IP-PBX | Linux, Windows | Proprietary | SIP | TLS, SRTP | Unified communications, conference calls, remote worker support and voicemail | Small businesses, Mid-large enterprises | 4.1; December 2013 |
Elastix | Linux | Proprietary | SIP, IAX, H.323, XMPP | TLS, SRTP | Unified communication server that also supports chat, mail and fax. | Capacity dependent on server design, scalable across multiple servers | 5.0.0; December 7, 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 | 1.10.11 (December 22, 2023 [66] ) [±] |
FreePBX | Linux, BSD, Solaris | GPL | SIP, IAX, H.323, 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 |
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 |
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 | 5.2.8; October 2020 |
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 | 6.3; February 2021 |
This section needs expansion. You can help by adding to it. (July 2016) |
This section needs to be updated.(November 2024) |
The following table is an overview of those VoIP clients which (can) 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 | |||
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ZRTP | ECDH | DTLS | SRTP | ||||||||
FaceTime | Active | No [67] | No [67] | ? | ? | ? | ? | Yes [67] | ? | No | No |
Jami | Active | Yes | Yes | No | ? | Yes | Yes | Yes | ? | Yes | ? |
Jitsi [b] | Active | Yes | Yes [67] | Yes | No | Yes | Yes | Yes [67] | Yes | Yes | ? |
Line [68] [69] | Active | No | ? | ? | ? | ? | ? | ? | ? | No [68] | No |
Linphone [b] | Active | Yes | Yes | Yes | ? | Yes | Yes | Yes | Yes | ? | No |
Signal | Active | Yes | Yes [67] | No | Yes | No | Yes | Yes [67] | Yes | Yes | Depends [70] |
Skype (opt-in per conversation, one pair of devices per conversation) [71] | Active | No | Yes [72] | No | No | No | Yes [73] | ? | ? | No | No |
Telegram | Active | Yes | Yes [74] | No | No | No | No | Yes | ? | No | No |
Threema | Active | Partially [c] [75] | Yes [76] | No | Yes [76] | Yes [76] | Yes [76] | Partially [d] [76] | Yes | No | No |
Viber [44] | Active | No | ? | ? | ? | ? | ? | ? | ? | ? | No |
Active | Partially [c] [77] | Yes [77] | No | Yes [77] | No | Yes [77] | Yes [77] | Yes [77] | Yes [77] | No | |
Wire | Active | Yes | Yes [78] | No | ? | Yes [49] | Yes [49] | Yes [79] | Yes | Yes | No |
Zfone | Abandonware | Viewable source [80] | Yes | Yes | Optional [81] | ? | Yes [82] | Yes | Yes | ? | ? |
The following table is an overview of those VoIP clients which (normally) provide client-to-server encryption.
Client name | Encryption protocols |
---|---|
Skype [67] | A custom protocol |
The Session Initiation Protocol (SIP) is a signaling protocol used for initiating, maintaining, and terminating communication sessions that include voice, video and messaging applications. SIP is used in Internet telephony, in private IP telephone systems, as well as mobile phone calling over LTE (VoLTE).
Voice over Internet Protocol (VoIP), also known as IP telephony, refers to a set of technologies used for voice communication sessions over Internet Protocol (IP) networks, such as the Internet. VoIP enables voice calls to be transmitted as data packets, facilitating various methods of voice communication, including traditional applications like Skype, Microsoft Teams, Google Voice, and VoIP phones. Regular telephones can also be used for VoIP by connecting them to the Internet via analog telephone adapters (ATAs), which convert traditional telephone signals into digital data packets that can be transmitted over IP networks.
Skype is a proprietary telecommunications application operated by Skype Technologies, a division of Microsoft, best known for IP-based videotelephony, videoconferencing and voice calls. It also has instant messaging, file transfer, debit-based calls to landline and mobile telephones, and other features. It is available on various desktop, mobile, and video game console platforms.
The landscape for instant messaging involves cross-platform instant messaging clients that can handle one or multiple protocols. Clients that use the same protocol can typically federate and talk to one another. The following table compares general and technical information for cross-platform instant messaging clients in active development, each of which have their own article that provide further information.
End-to-end encryption (E2EE) is a method of implementing a secure communication system where only communicating users can participate. No one else, including the system provider, telecom providers, Internet providers or malicious actors, can access the cryptographic keys needed to read or send messages.
Skype for Business Server is real-time communications server software that provides the infrastructure for enterprise instant messaging, presence, VoIP, ad hoc and structured conferences and PSTN connectivity through a third-party gateway or SIP trunk. These features are available within an organization, between organizations and with external users on the public internet or standard phones.
Gizmo5 was a voice over IP communications network and a proprietary freeware soft phone for that network. On November 12, 2009, Google announced that it had acquired Gizmo5. On March 4, 2011, Google announced that the service would be discontinued as of April 3, 2011.
QuteCom was a free-software SIP-compliant VoIP client developed by the QuteCom community under the GPL-2.0-or-later license. It allows users to speak to other users of SIP-compliant VoIP software at no cost. It also allows users to call landlines and cell phones, send SMS and make video calls. None of these functions are tied to a particular provider, allowing users to choose among any SIP provider.
ZRTP is a cryptographic key-agreement protocol to negotiate the keys for encryption between two end points in a Voice over IP (VoIP) phone telephony call based on the Real-time Transport Protocol. It uses Diffie–Hellman key exchange and the Secure Real-time Transport Protocol (SRTP) for encryption. ZRTP was developed by Phil Zimmermann, with help from Bryce Wilcox-O'Hearn, Colin Plumb, Jon Callas and Alan Johnston and was submitted to the Internet Engineering Task Force (IETF) by Zimmermann, Callas and Johnston on March 5, 2006 and published on April 11, 2011 as RFC 6189.
Linphone is a free voice over IP softphone, SIP client and service. It may be used for audio and video direct calls and calls through any VoIP softswitch or IP-PBX. Linphone also provides the possibility to exchange instant messages. It has a simple multilanguage interface based on Qt for GUI and can also be run as a console-mode application on Linux.
Jami is a SIP-compatible distributed peer-to-peer softphone and SIP-based instant messenger for Linux, Microsoft Windows, macOS, iOS, and Android. Jami was developed and maintained by the Canadian company Savoir-faire Linux, and with the help of a global community of users and contributors, Jami positions itself as a potential free Skype replacement.
Matthew Rosenfeld, better known by the pseudonym Moxie Marlinspike, is an American entrepreneur, cryptographer, and computer security researcher. Marlinspike is the creator of Signal, co-founder of the Signal Technology Foundation, and served as the first CEO of Signal Messenger LLC. He is also a co-author of the Signal Protocol encryption used by Signal, WhatsApp, Google Messages, Facebook Messenger, and Skype.
Rakuten Viber, or simply Viber, is a cross-platform voice over IP (VoIP) and instant messaging (IM) software application owned by Japanese multinational company Rakuten, provided as freeware for the Google Android, iOS, Microsoft Windows, Apple macOS and Linux platforms. Users are registered and identified through a cellular telephone number, although the service is accessible on desktop platforms without needing mobile connectivity. In addition to instant messaging it allows users to exchange media such as images and video records, and also provides a paid international landline and mobile calling service called Rakuten Viber Out. As of 2018, there are over a billion registered users on the network.
TextSecure was an encrypted messaging application for Android that was developed from 2010 to 2015. It was a predecessor to Signal and the first application to use the Signal Protocol, which has since been implemented into WhatsApp and other applications. TextSecure used end-to-end encryption to secure the transmission of text messages, group messages, attachments and media messages to other TextSecure users.
Open Whisper Systems was a software development group that was founded by Moxie Marlinspike in 2013. The group picked up the open source development of TextSecure and RedPhone, and was later responsible for starting the development of the Signal Protocol and the Signal messaging app. In 2018, Signal Messenger was incorporated as an LLC by Moxie Marlinspike and Brian Acton and then rolled under the independent 501c3 non-profit Signal Technology Foundation. Today, the Signal app is developed by Signal Messenger LLC, which is funded by the Signal Technology Foundation.
Wire Swiss GmbH is a software company with headquarters in Zug, Switzerland. Its development center is in Berlin, Germany. The company is best known for its messaging application called Wire.
Signal is an open-source, encrypted messaging service for instant messaging, voice calls, and video calls. The instant messaging function includes sending text, voice notes, images, videos, and other files. Communication may be one-to-one between users or may involve group messaging.
In cryptography, the Double Ratchet Algorithm is a key management algorithm that was developed by Trevor Perrin and Moxie Marlinspike in 2013. It can be used as part of a cryptographic protocol to provide end-to-end encryption for instant messaging. After an initial key exchange it manages the ongoing renewal and maintenance of short-lived session keys. It combines a cryptographic so-called "ratchet" based on the Diffie–Hellman key exchange (DH) and a ratchet based on a key derivation function (KDF), such as a hash function, and is therefore called a double ratchet.
The Signal Protocol is a non-federated cryptographic protocol that provides end-to-end encryption for voice and instant messaging conversations. The protocol was developed by Open Whisper Systems in 2013 and was introduced in the open-source TextSecure app, which later became Signal. Several closed-source applications have implemented the protocol, such as WhatsApp, which is said to encrypt the conversations of "more than a billion people worldwide" or Google who provides end-to-end encryption by default to all RCS-based conversations between users of their Google Messages app for one-to-one conversations. Facebook Messenger also say they offer the protocol for optional Secret Conversations, as does Skype for its Private Conversations.
Comparison of user features of messaging platforms refers to a comparison of all the various user features of various electronic instant messaging platforms. This includes a wide variety of resources; it includes standalone apps, platforms within websites, computer software, and various internal functions available on specific devices, such as iMessage for iPhones.
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.
Note: Private conversations can only be accessed on one device at a time.
Users can verify the security of their conversations by checking the key setup between two users.
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.
New encryption keys are used for each message, so a compromised key has minimal impact.