This list of SIP software documents notable software applications which use Session Initiation Protocol (SIP) as a voice over IP (VoIP) protocol.
Free and open-source license
Asterisk
Cipango SipServlets 1.1 application server
Elastix
FreeSWITCH
FreePBX
GNU SIP Witch
Kamailio, formerly OpenSER
Mobicents Platform (JSLEE[2] 1.0 compliant and SIP Servlets 1.1 compliant application server)
Mysipswitch
OpenSIPS, fork of OpenSER
SailFin
SIP Express Router (SER)
Enterprise Communications System sipXecs
Yate
YXA, based on Erlang
3Com VCX IP telephony module: back-to-back user agent SIP PBX
3CX Phone System, for Windows, Debian 8 GNU/Linux
Aastra 5000, 800, MX-ONE
Alcatel-Lucent 5060 IP Call server
Aricent SIP UA stack, B2BUA, proxy, VoLTE/RCS Client
AskoziaPBX
Avaya Application Server 5300 (AS5300), JITC certified ASSIP VoIP
Bicom Systems IP PBX for telecoms
Brekeke SIP Server, SIP proxy, SIP registrar, SIP NAT, TCP/UDP
Cisco SIP Proxy Server, Cisco unified border element (CUBE), Cisco Unified Communication Manager (CUCM)
CommuniGate Pro, virtualized PBX for IP Centrex hosting, voicemail services, self-care, ...
Comverse Technology softswitch, media applications, SIP registrars
Creacode SIP Application Server Real-time SIP call controller and IVR solution for carrier-class VoIP networks
Dialogic Corporation Powermedia Media Servers, audio and video SIP IVR, media and conferencing servers for Enterprise and Carriers.
Dialexia VoIP Softswitches, IP PBX for medium and enterprise organizations, billing servers.
IBM WebSphere Application Server - Converged HTTP and SIP container JEE Application Server
Interactive Intelligence Windows-based IP PBX for small, medium and enterprise organizations
Kerio Operator, IP PBX for small and medium enterprises
MERA Systems VoIP softswitches with sbc, H.323/SIP proxy
Microsoft Lync Server 2010 & 2013
Mitel Communications Director
NEC SV7000 back-to-back user agent SIP PBX
NEC UNIVERGE 3C Unified Communications and Collaboration software
Nokia Siemens Networks hiQ8000
Nortel SCS500
Nortel SIP Multimedia Communication Server 5200
Objectworld UC Server
Oracle Communications Converged Application Server (OCCAS)
Oracle WebLogic SIP Server
Spirent SIP Server Platform
ShoreTel IP phone systems with unified communications and contact center built in
Unify OpenScape Voice, OpenScape 8000 SIP softswitch, mediaserver, ... (SIP)
Snom One free/blue/yellow (Snom acquired and renamed pbxnsip) (SIP)
Speedflow Communications VoIP class 4/5 softswitches with integated billing, transcoding, SIP-H.323 converter.
Sun Microsystems Sun GlassFish Communication Server
Tadiran Telecom Coral Ipx family and Aeonix softswitch
Tandberg Video Communication Server - SIP application server, media server and H.323 gateway
TrueConf Server - video conferencing server software, SIP gateway
Unison Unified communications software
Voice Elements Inventive Labs' .NET Voice Development software and SIP stack platform.
Zultys MX250/MX30 IP PBXs for SMB and enterprise
Wildix WGW series Unified communication platform up to 5000 users on a single server. Up to 65535 users on WMS network
REVE Systems Mobile VoIP, Class 4/5 Softswitch with integrated billing and Bandwidth Optimization solutions
Free and open-source license
Blink, OSX, Linux, and Windows
Ekiga, formerly named GnomeMeeting, GPL
Empathy, using GTK+ libraries and Telepathy framework, GPL
Jitsi, a Java VoIP and Instant Messaging client with ZRTP encryption, for FreeBSD, Linux, OS X, Windows; LGPL
KPhone, using Qt libraries, GPL, for Linux
Linphone, with a core/UI separation, the GUI is using GTK+ libraries, for Linux, OS X, Windows, and mobile phones (Android, iPhone, Windows Phone, BlackBerry)
MicroSIP, lightweight softphone, using PJSIP stack, for Windows
QuteCom, formerly named OpenWengo, using Qt libraries, GPL, for Windows, Mac, and RPM- DEB-based Linux
Ring, with GTK+/Qt GUI, also supports IAX2 protocol, for Linux, OS X, Windows GPL
Telephone, OS X softphone written in Cocoa/Objective-C
Twinkle, using Qt libraries, GPL, for Linux
Yate client, using Qt libraries, GPL
Blink, for Mac
eyeBeam and X-Lite, for Windows, OS X
LifeSize Desktop, for Windows
Phoner and PhonerLite, for Windows, Voice: G.711, G.722, G.726, GSM, iLBC, Speex, Opus; security: TLS, SRTP, ZRTP
Polycom PVX, for Windows. Voice: G.711, G.722, G.722.1, G.728, G.729A, Siren Codec; Video: H.261, H.263, H.264; Data: T.120, People+ Content, H.239, H.323 Annex Q far-end camera control
Windows Messenger versions 4 and 5 (not to be confused with Windows Live Messenger or MSN Messenger which do not support SIP)
Gizmo5, formerly PhoneGaim, based on Pidgin
Free and open-source license
Sipdroid for Android, GPL v3
Linphone for Android, BlackBerry, iPhone, Windows phone; GPL v2
CSipSimple for Android, GPL v3
Ring for Android, GPL v3
Acrobits for iOS and Android
Acme Packet Session Director
Audiocodes Mediant
Genband Quantix SBC
Ingate Systems Ingate SIParators
Metaswitch Perimeta
Sonus Networks NBS (Sonus acquired NET)
Kamailio
Check Point VPN-1 firewalls, include complete SIP support for multiple vendors
Intertex SIP transparent routers, firewalls and ADSL modems, for broadband deployments and SOHO market
IPFire Linux-based firewall distribution which comes with Quality of service (QoS) to prefer VoIP communications as well as with Asterisk.
Cisco PIX/ASA firewalls include complete SIP support
The firewall feature in Cisco IOS includes complete SIP support
Secure Computing, SnapGear firewall includes siproxd SIP proxy, Sidewinder 7 firewall includes a SIP proxy
SonicWall, supports SIP
D-Link Firewall DFL-210/260/800/860/1600/2500 supports SIP (SIP-ALG) with firmware 2.20.01.05 and above
ZyXEL ZyWALL P1, 2Plus, 5 UTM, 35 UTM, 70 UTM, 1050, USG 100, USG 200, USG 300, USG 1000 supports SIP-ALG
Fortinet, all FortiGates running v280/v300 builds
Linux Netfilter's SIP conntrack helper fully understands SIP and can classify (for QOS) and NAT all related traffic
Juniper Networks Netscreen and SRX firewalls include complete SIP Application Layer Gateway support
Netopia Netopia supports ALG
PF, built-in OpenBSD firewall PF can handle the NAT through the "static-port" directive and the bandwidth control through the built-in queuing system of SIP connections
pfSense, a firewall/router distribution based on FreeBSD and PF; has QoS that properly tags VoIP traffic and a SIP proxy package that is available for NATed endpoints. Its functionality can be expanded with packages like FreeSWITCH, a free/open source software communications platform for making SIP, voice and chat driven products.
oSIP
Ixia (company) commercial SIP-VoIP and Video test and emulation and load test platform
Mu Dynamics: commercial SIP-VoIP, RTSP-IPTV Triple Play service assurance platform
Codenomicon Defensics: commercial test automation framework
List of SIP software Wikipedia (Text) CC BY-SA
