Comparison of VoIP software

Voice over IP (VoIP) software is used to conduct telephone-like voice conversations across IP based networks. For residential markets, VOIP phone service is often cheaper than traditional PSTN phone service and can remove geographic restrictions to telephone numbers (i.e. have a "New York" PSTN phone number in Tokyo).

For enterprise or business markets, VoIP enables the enterprise to manage a single network (the IP network) instead of separate voice and data networks, while enabling advanced and flexible capabilities to the end user.

General softphone clients

Program	Operating systems	License	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
Abbeyphone	Windows XP/2000	Closed Proprietary	SIP
AGEphone	Windows XP/2000/Vista, Windows Mobile	Trialware version / Closed Proprietary	SIP, SDP, RTP, STUN, UPnP		Recording, Voice Mail, Multiple Services at Once, Outlook Support, Call Forwarding	1.67 Windows, 1.71 Mobile
AOL Instant Messenger	MS Windows, Mac OS, Linux	Freeware	SIP, RTP		Video, file transfer, PC to phone, phone to PC
BitWise IM	Linux, Mac OS X, Windows	Freeware / Closed Proprietary		Blowfish	File transfer, whiteboard	1.7.2
Brosix	Windows	Freeware / Closed Proprietary		AES	Text chat, Video, File transfer, Whiteboard, Co-Browse, Voice mail, Voice conference	1.9.2
Cisco IP Communicator	Windows	Closed Proprietary	SCCP (Skinny), SIP, TFTP			2.1.2 (September 17, 2007)
Coccinella	FreeBSD, Linux, Mac OS X, Windows	GPL Free software	XMPP, IAX	Supports TLS/SSL and SASL	File transfer, whiteboard	Template:Latest stable release/Coccinella
Comneon	Windows 2000/XP/Vista, Windows Mobile, Linux, Brew, APOXI	Closed Proprietary	SIP, SDP, RTP, STUN, MSRP, XCAP	HTTP Digest, IMS AKA	IMS/IETF SIP dual mode Video, VoIP, PoC, IM, Chat, Presence, File Sharing H.263, H.264 G.711, AMR	3.5
Cornfed SIP User Agent	Linux	Freeware / Closed Proprietary	SIP, SDP, RTP, STUN		Command-Line Interface (CLI) and Gnome GUI clients	1.0.1
CounterPath Bria	Windows & Mac	Closed Proprietary	SIP, STUN, ICE	SRTP, TLS	Contact centric interface, Customizable Skinning engine, eyeBeam Feature set	2.1
CounterPath eyeBeam	Windows, Mac, Linux	Closed Proprietary	SIP, STUN, ICE	SRTP, TLS	Video, IM, Conferencing, Multiple login account, QoS, Outlook integration, Call transfer, 6 lines	1.5
CounterPath X-Lite	Windows, Mac, Linux	Freeware	SIP, STUN, ICE		IM, single login account, for Windows and Mac also Conferencing, Video and SIMPLE based presence]	Windows and Mac: 3.0, Linux: 2.0
damaka	Windows	Freeware	SIP	Always end-to-end encrypted using unspecified algorithm.	CallOuts, video, desktop sharing, voice commands, file-sharing, SMS, IP Radio, RSS reader	2.5 (December 26, 2006)
ComunIP ClicVoz	Windows, Linux	Closed Proprietary	SIP, SDP, ICE (draft-17), STUN, proprietary HTTPS Tunneling Protocol, RTP, TFTP	TLS/SSL	G.711, G.726, G.729, GSM, iLBC, Speex audio codecs AEC, AGC, VAD Instant Messaging File transfer Contact Management USB Phone inputs ATA conformance	2.5.0 (July 31, 2007)
Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
Ekiga (formerly GnomeMeeting)	Linux, (Beta Windows support)	GPL Free software	SIP, H.323, STUN, Zeroconf		Video, IM, LDAP, Call Forwarding, Call Transfer	2.0.12 (March 10, 2008)
Express Talk	Windows, Mac OS X, Windows CE	Freeware version, Licensed version.	SIP		6 Lines, multiple accounts, conferencing, transfers, recording, push-to-talk (intercom)	2.04
Eyeball Chat	Windows	Freeware			Free VoIP, video and IM	2.2
FaramPhone	Windows XP/Vista/2000/2003	Closed Proprietary	SIP, SDP, RTP		G.711,AMR,Speex,GSM H.263, MPEG4 Audio and Video Call, DTMF, 2 Lines Audio and video Conference (5 parties) Video Mail,Call Forwarding, Call Transfer Video Recording to 3gp file, Call History,Friends List	1.1.0 (May,17,2008)
Gizmo5 Desktop (formerly known as Gizmo Project)	Linux, Mac OS X, Windows XP/2000	Freeware	SIP, XMPP, Jabber	SRTP	Recording, voicemail, Jabber IM, Gizmo to phone, phone to Gizmo, Talk with Yahoo! Messenger, Google Talk, or Windows Live user	4.0.0.369 2008 May 21 -Windows 3.1.2 (v222) 2007 Oct 31 -MacOS (As of May '08)
Globe7	Linux, Mac OS X, Windows XP/2000	Freeware	SIP	SRTP	Call landline, mobile, VOD, SMS, Free US DID number.	7.2.0.0 April 12, 2007
Google Talk	Windows XP/2000	Freeware (libjingle is Free software	XMPP, Jabber		Chat, file transfer, voicemail, mail via "GMail Integration"	1.0.0.104
GoSIP	Linux, Mac OS X, Windows XP/2000,Windows Mobile	Freeware	SIP			January, 2007
iCall	Windows Vista/XP/2000	Closed Proprietary	SIP		Voicemail	2.0.0.58
iChat AV	Mac	Closed Proprietary	SIP AIM ICQ Jabber H263 H264		Integrated, PBX independent	January 2007
iSoftPhone	Mac OS X	Shareware	SIP, STUN, RTP		Address Book Integration, Daylite CRM Integration, Call Recording, IM, Conferencing, Mulitple Providers, Simple Setup, Call transfer, 5 lines	2.0 - released Jan 2008
TABLETmedia iFon	Windows Mobile 2003/2003SE/5.0, WindowsCE 4.x/5.x	Commercial	SIP, H.261, H.263, G.711, G.722, G.723.1, G.729A, GSM, AMR	Optional: MD5/Digest, DES, AES	Mobile VoIP, videoconferencing, messaging, dual-mode devices support	5.10.59
iVisit	Windows & Mac	Freeware / Closed Proprietary	Proprietary P2P protocol		8-way videoconferencing, file sharing, recording in QuickTime format	3.6.3 (verified on July 7th, 2006)
Intellivic Softphone	Windows 2000/XP/Vista	Closed Proprietary/ Freeware	SIP, SDP, RTP, UPnP, NAT-PMP, STUN, TURN	TLS, HTTPS	inherits all features of Intellivic SDK features and skin fully customizable	4.1
Jabbin	Linux, Windows	GPL Free software	Libjingle, XMPP, Jabber	SSL	Instant messaging, file transfer, compatible with Google Talk	2.0b2
KCall	Linux (KDE)	GPL / LGPL Free software	SIP			0.7.0 (2nd August 2005)
Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
KPhone	Linux (KDE)	GPL Free software	SIP, STUN, NAPTR/SRV	SRTP	Video, voice, IM, external Sessions, IPv6 support for UDP	1.0.2 (22nd September 2006)
Linphone	Linux and Microsoft Windows	GPL Free software	SIP		Video, IM, STUN, IPv6	1.7.1 (16 April 2007)
Lotus Sametime	Linux and Microsoft Windows, Mac OS X	Closed Proprietary	SIP, SIMPLE, T.120 and H.323			7.5.1 (April 2007)
Lynxphone	Windows, Mac OS X, Linux, NetBSD, FreeBSD	Freeware	SIP, STUN, ICE	SRTP, TLS	Voice only, multiple-language support, Windows Address Book integration, skins, custom ringtones	0.6.0
MindSpring (formerly Vling)	Windows 2000, Windows XP	Freeware	SIP, XMPP		Instant messaging, PC to phone, file transfer	2.0
Minisip	Windows XP, 2000, Linux, Windows Mobile	GPL / LGPL Free software	SIP	SRTP, TLS, MIKEY (DH, PSK, PKE), end to end encryption	Video, IM Conferencing
Minipax	Windows Vista, XP, 2000	Freeware	SIP	Voip Tunnelling or VPN	Supports G723.1,GSM,G711, G729 Available on separate download,Call recording, Acoustic Echo Canceller	2.7.4.1
Mirial Softphone (Mirial, formerly DyLogic)	Windows 2000/XP/2003/Vista	Closed Proprietary	SIP, H.323, RTSP		H.264 HD 720p 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 camera input Presentation (H.239, RFC-4796) Acoustic Echo Canceller Audio denoise filter Far End Camera Control GPU accel (D3D and OpenGL)	6.0 (February 20, 2008)
Mizuphone	Windows 2000/XP/2003/Vista	Freeware Closed Proprietary	SIP, SDP, RTP, STUN, ICE, UPnP, TLS, Tunneling Protocol, Ultra-wideband, G.711, G.723.1, G.729A, iLBC, MPEG4, MJPG, H263,, H264, SIMPLE	SSL/TLS, SRTP	Multiple accounts, multiple SIP server registrations File transfer,File-Sharing and Remote Desktop over SIP IM, Presence, HD quality video Local and remote VoiceMail Mute, Hold, Redial, Transfer, Forward, Conference DTMF (inband DTMF or SIP INFO messages) AEC, AGC, VAD, Noise Supression, Auto QoS, Dynamic Jitter UPNP, STUN, ICE, firewall and NAT traversal Codecs: G711 (PCMU,PCMA), G.723.1, G729, iLBC, MPEG1, MPEG4, Theora, H263,H264, MJPG Balance/credit display Outlook, LDAP, XCAP synchronization and remote profile storage History (with voice and video recording) Fully encypted communications (signaling and media too) Costumizable (skin,features,language)	0.9.2 (July 17, 2008)
Movial Communicator	Windows 2000/XP/Vista	Closed Proprietary	SIP, RTP, STUN, XCAP		IMS and IETF compatible IM, Chat, Presence, VoIP, Video, File transfer H.263, H.264 HD video G.723, G.729, AMR, ISAC, iLBC audio Outlook connector Customizable GUI
Mumble	Windows, OSX, Linux, and BSD (server)	GPLv2	Speex	SSL	High Quality Audio Chat with (limited) embedded HTML ACLs for user management Customizable In-Game Overlay Directional Audio Plugin Support Nested Channels	1.1.4
ooVoo	Windows / Mac OS X	Shareware	Proprietary codec based on On2 TrueMotion VP7, Polycom Siren 14		Up to six person multiparty video calls, video messages, instant text messaging, file transfer	1.1
PortSIP	Win32(2000/XP/2003/Vista/2008), WinCE/Windows Mobile, Symbian.	Voip SDK OEM Free software	SIP, SIMPLE XMPP, Audio/Video, Conference,SDP, RTP, RTCP, STUN, TURN,		Provide SDK. Customisation for ITSP	3.0
PeerMe	Windows 2000 or Windows XP	Freeware	?
PhoneGaim	Linux (Linspire), Windows XP/2000	GPL free software	SIP
Phoner and PhonerLite	Windows	Freeware	SIP, CAPI	TLS, SRTP	recording, voicemail	Phoner: 2.17 (May 22nd, 2008), PhonerLite: 1.44 (May 22nd, 2008)
Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
PJSIP	Linux, Win32 (NT/200/XP), WinCE/Windows Mobile, Mac OS X, FreeBSD, RTEMS, Symbian, etc	GPL free software/Closed Proprietary	SIP, SIMPLE, SDP, RTP, RTCP, STUN, TURN, ICE	TLS, SRTP	Media stack, NAT traversal (STUN/TURN/ICE), Python API	0.8.0 (11 Nov 2007)
Remote Origin, Inc.	Windows	Closed Proprietary	IAX2	Digest-Authentication	TTY, USB Token DRM	1.0 (March 1st, 2007)
SightSpeed	Mac OS X / Windows	Freeware	SIP,RTP,Proprietary P2P protocol		video, voicemail, phone in, phone out, multiparty calling, conference recording, text messaging, NAT traversal, video mail	6.0
SIP Communicator	Linux, Mac, Windows XP/2000 (all java supported)	LGPL free software	SIP/SIMPLE, Jabber		Text messaging
Sippax	Windowx Vista,XP,2000	Closed Proprietary	SIP	Voip Tunelling (VPN)	Support Audio and Video Address book Call Log Skin customization private branding/logo
SJphone	Windows 2000/Windows XP, Windows Vista, Mac OS X, Linux, Windows Mobile 5	Freeware	SIP, RTP, STUN, Jabber, H.323		Customisation for ITSP	Windows XP/Vista: 1.65 beta (Mar 27.2007)
Skype	Windows 2000/XP, Mac OS X, Linux(32-bit i386 only), Windows Mobile	Freeware	Proprietary P2P protocol	Encrypted	Video, file transfer, voicemail, Skype to phone, phone to Skype, additional P2P extensions (games, whiteboard, etc...)	Windows: 3.8.0.115, (as of Apr. 29, 2008), Linux: 2.0.0.68, Mac OS X: 2.7.0.257 (as of Feb. 13, 2008), Windows Mobile: 2.2.0.37 (as of Nov. 7, 2007)
SmeetX, Smeet SDK	Linux, Microsoft Windows	Closed Proprietary	SIP, H.323, STUN, proprietary P2P protocol	Optional encryption plugin	Video (H.263, H.263+, MPEG-4 and H.264), ActiveX control, XML, SOAP	1.3.3 (as of April 2007)
Switchboard, The	Windows 2000/XP, Mac OS X, Linux, OS/2, and any other Java enabled platform	Freeware	Proprietary P2P protocol	Encrypted	web-based (no installation), conferencing, file transfer, ICQ, AIM, and MSN compatibility	3.2 (March 2007)
Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
Teamspeak	Windows, Linux, Mac OS X (unofficial)	Freeware Closed Proprietary			conferencing	2.0.32.60
Tivi	Windows, many cell phones, Nokia smartphones	Freeware			tivi-to-land line	Video call: 0.127a, Lite: 0.602.
Twinkle	Linux	GPL free software	SIP	SRTP, ZRTP		1.1 (July 21, 2007)
Vbuzzer	Windows XP	Closed / Proprietary freeware	SIP	TLS	IM (MSN), voicemail, personalized voice greeting.	2.0.282
VoipDiscount	Windows 2000/XP/Vista	Freeware	SIP
VOIspeed	Windows 2000/XP	Freeware	SIP		IPBX, IVR, CRM integration, LCR, Voicemail	4
vPhone	Windows	Freeware + proprietary	SIP, GSM, VOIP		Conferencing, address book, SMS, chat
VoipGATE Softphone	Windows 2000/XP/Vista	freeware	IAX2 protocol		address book, SMS, chat	v2.08 (Dec 2007)
WengoPhone	Linux, Mac OS X, Windows XP/2000, SmartPhone, Windows Mobile	GPL free software	SIP	AES-128|	Video, IM (MSN, AIM, ICQ, Yahoo!, Jabber, GoogleTalk), voicemail, wengo to phone.	v2.1.0 (May 15, 2007)
Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
Windows Live Messenger	Windows 2000/XP	Freeware	SIP, RTP, proprietary		Video, voice, chat, text messaging, PC to Phone
wxCommunicator	Windows XP/2000	GPL free software	SIP, STUN, TURN, ICE,		Voice, chat, recording, conferencing, multiple sip profiles
Yahoo! Messenger	Microsoft Windows, Mac OS (8, 9, X), (Linux/FreeBSD version not VoIP capable)	Freeware	SIP (using TLS) and RTP (media)		Video, file transfer, PC to phone, phone to PC
YakaPhone	Microsoft Windows, Mac OS (8, 9, X), (Linux/FreeBSD)	Freeware	IAX, IAX2		Audio, Video, Text & SMS, PC to phone, phone to PC
XMeeting	Mac OS X	BSD free software	SIP, H323, STUN		Video, call recording	v0.3.4a
Zfone (formerly PGPfone)	Linux, Mac OS X, Windows	Viewable source / Proprietary license (includes time bomb provision)	SIP and RTP	SRTP, ZRTP		Beta (6th of December 2006)
Zoiper (formerly Idefisk)	Linux, Mac OS X, Windows 2000, Windows XP, Windows Vista	Freeware / Proprietary	SIP, RTP, STUN, T.38, IAX, IAX2	TLS, SRTP	T.38 Fax Native conferencing API Outlook integration Attended transfer Automatic provisioning(XML) Changeable number of lines Call recording URL handling Outlook/Thunderbird integration Echo cancellation Multilanguage support	Windows: 2.15 - 17 June 2008, Linux: 2.04, Mac OS X: 2.04 - July 2008
Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release

Hosted services

Program	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
EasyIVR	Closed Proprietary	Proprietary Protocol		Virtual ACD, IVR, Voice Broadcasting, Development environment,	12
EvaPhone.com	Closed source Freeware	RTMP		Web based softphone	2008
HarmonicaPhones	Closed Proprietary	Proprietary Protocol		VirtualPBX, Conferencing, ACD, Development environment, Flash UI	2.3
Vidivic	Closed Proprietary	SIP, SDP, RTP, UPnP, NAT-PMP, STUN, TURN	TLS, HTTPS	Intellivic SDK feature set Conferencing solution Ad-hoc and scheduled conferences PSTN dial-in	1.0
Jajah	Closed source			Connects together two conventional phones.
Loquaxity	Closed source	IAX2 SIP	Transport Layer Security	Click-to-Call, ACD, Co-browse

PDA specific

Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
HipVoice	WinCE 4.2, PocketPC, Windows Mobile 5.0, CE 5.0	Proprietary	XMPP, Jabber	Proprietary algorithm	Unicast & Multicast Push-To-Talk	3.1
Express Talk	Windows Pocket PC or Windows Mobile OS (all versions since 2002)	Closed / Proprietary	SIP,G.711, GSM		2 Lines, On Hold, Push-to-Talk	v2.07
TABLETmedia iFon	Windows Mobile 2003/2003SE/5.0, WindowsCE 4.x/5.x	Commercial	SIP, H.261, H.263, G.711, G.722, G.723.1, G.729A, GSM, AMR	Optional: MD5/Digest, DES, AES	Mobile VoIP, videoconferencing, messaging, dual-mode devices support	5.10.59
Intellivic Smartphone	Windows Mobile5/Mobile6	Closed Proprietary	SIP, SDP, RTP, UPnP, NAT-PMP, STUN, TURN	TLS, HTTPS, VPN	Intellivic SDK feature set IMR/VCC	1.2

Mobile phones

Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Latest release
Eyeball Mobile Messenger	Windows Mobile 5 or 2003, Linux, uclinux	Proprietary software	XMPP, SIP, STUN, TURN, ICE	HTTPS	VoIP, Presence, Messaging & Video Telephony	v.7.1
iSkoot	Windows Mobile 5 or 6, BlackBerry, UIQ, Symbian 9, J2ME, Palm OS 5	Freeware	Skype	HTTPS	Presence, Messaging, Authorization	v1.1
fring	Symbian 8 or 9, Windows Mobile 5 or 6, iPhone	proprietary	SIP, Skype, Google Talk, MSN Messenger, Twitter, ICQ, AIM, Yahoo
Gizmo5 Mobile	Java (J2ME?), Nokia	Proprietary freeware	SIP?, Recording?, voicemail?, Jabber IM, Gizmo ↔ phone, Yahoo! Messenger, or Windows Live user	?		1.15 (as of May '08)
TABLETmedia iTalkie	Windows 2000/XP, Windows Mobile 2003/2003SE/5.0, WindowsCE 4.x/5.x	Commercial		Optional: MD5/Digest, DES, AES	serverless Push-to-Talk with presence and direct calling (VoIP)	1.46
Intellivic Smartphone	Windows Mobile5/Mobile6	Closed Proprietary	SIP, SDP, RTP, UPnP, NAT-PMP, STUN, TURN	TLS, HTTPS, VPN	Intellivic SDK feature set IMR/VCC	1.2
Windows Mobile 6	Windows Mobile 6 Professional/Standard	Freeware	SIP

Frameworks and libraries

Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Key and target markets	Latest release
Telepathy/Farsight	Linux, MacOSX, Windows	LGPL free software	SIP, XMPP (Jingle), ICE (STUN/TURN), UPnP	None yet	Multi-user A/V conferencing, IM, collaborative applications	Mobile devices (Maemo), Linux Desktop	spec 0.17.8 (24-Jul-2008)
PortSIP VoIP SDK	Windows, Windows Mobile, Symbian	Commercial	SIP, SDP, STUN, TURN	TLS, DTLS, S/MIME, Identity, Digest-Authentication	Audio/Video call, SIMPLE Presence, IM, XMPP, Audio/Video conference, audio/video recording	G729, G723.1, GSM, iLBC, GSM, PCMA, PCMU, H263, H263+, H264.	4.2 (June 10th, 2008)
Tapioca	Linux	GPL free software	Telepathy (software)				0.3.9 (June 12, 2006)
SDTU	Linux (must support tcp_nodelay for full capablities)	GPL free software	SDTU , gsm over tcp		Ability to send parallel stream (i.e. for videoconferencing)		0.1.7 (26-Jan-2003 13:27)
ComunIP VoxBR	Windows, Linux	Closed Proprietary	SIP, SDP, ICE (draft-17), STUN, proprietary HTTPS Tunneling Protocol, RTP, TFTP	SSL/TLS	Fast-CGI integration (PHP backend), IRC protocol support	Client and server-side applications, Software SBCs, VoIP Middleware (including support of SaaS delivery model)	2.5.0 (July 31, 2007)
Intellivic SDK	Windows 2000/XP/Vista/EmbeddedXP/ WinCE/Mobile5/Mobile6	Closed Proprietary	SIP, SDP, RTP, UPnP, NAT-PMP, STUN, TURN	TLS, HTTPS	Standards: IMS, TISPAN, ETSI, 3GPP Filetransfer, IM, presence Contact management USB phone support	Client Applications	3.1
PCBest Network SIP SDK	Windows 2000/XP/Vista/	Closed Proprietary	SIP, SDP, RTP, STUN, TURN	TLS	AEC/AES, PLC	Client and Server Applications	1.60
Brekeke JTAPI SDK	Windows 2000/XP/Vista	Closed Proprietary	SIP, SDP, RTP, UPnP		Conference Calls Transfer Calls Recognize and Send DTMF	Server Applications, IVR	1.0
Brekeke PAL	Windows 2000/XP/Vista	Closed Proprietary	SIP		Park/Unpark Calls Third Party Call Control Transfer Calls	Operator Consoles	1.0
reSIProcate	Linux, Mac OS X, BSD, Windows	Vovida Software License (BSD-like open source)	SIP, SDP, STUN, TURN	TLS, DTLS, S/MIME, Identity, Digest-Authentication	SIP Stack, Dialog layer (DUM), Proxy (repro), TURN server (reTurn)	Client and Server implementations (session signaling, registration, presence, messaging), proxies	1.3.3 (July 3rd, 2008)

Server software

Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Key and target markets	Latest release
3CX phone system	Windows XP, 2000, 2003.	Freeware / Closed Proprietary	SIP		IP PBX, Provisioning, Fax, Bridges, SIP trunking support, Unified Messaging, Outlook and Exchange 2007 integration, Call Queuing, Auto Attendant, VOIP Client	SMB	5.0 (Dec 07)
4PSA VoipNow	Linux (i386, x86_64, ppc)	Open Source/Closed Source	SIP, IAX	SSL,TLS	Multitenant, Four levels management interface, Provisioning, Virtualization, Call routing, prepaid and postpaid billing, Call queues, Conferences, IVRs, Callback, Calling cards	Service provides, SMB	1.6.0, (May 15, 2008)
Asterisk PBX	Linux, BSD, Mac OS X	GPL free software / Proprietary	SIP, H.323, IAX				1.4.9.2, May 13, 2008
Axon PBX	Windows, Linux	Free Limited Version / 14 Day Trial Licensed / Closed Proprietary	SIP RFC 2543 and RFC 3261, H263, H261		Automatic "one-click" installer, Web control panel. Call transfer, hold, and record, call queue sequencer, Supports MD5 security authentication.	Carriers and ITSPs, Residential and Enterprise	2.0, March 27, 2008
Brekeke PBX	Windows and Linux	Free 60-day trial / Closed Proprietary	SIP		IP PBX, Voicemail, Conference, ARS, IVR, Auto Attendant, Queuing, Web service, Plugin APIs	Carriers, ITSP, Hosting Providers, Enterprise, SMB	2.1
Brekeke SIP Server	Windows, Linux, Mac OS and Solaris	Free Academic License / Free 60-day trial / Closed Proprietary	SIP		SIP Registrar/Proxy, NAT Traversal, Authentication, Dial Plan, Multiple-Domains Hosting, UDP/TCP Conversion, UPnP, Plugin APIs	Carriers, ITSP, Enterprise, SMB, R&D	2.1
BroadSoft BroadWorks	Linux and Solaris	Closed Proprietary	SIP		SIP Registrar/Proxy, Advanced Telephony Features, Audio Conferencing, Point-to-Point Videoconferencing, Mobile/Cellular Integration, Call Center/ACD, Regulatory Compliance, Desktop Productivity Applications (Windows based), Web Portal, PSTN Routing and Translations, Open APIs	Carriers and ITSPs, Residential and Enterprise	R14SP3
CallWeaver	Linux, BSD, Mac OS X, Solaris	GPL	SIP, H.323, IAX	SRTP	Mature T.38 pass-through and termination support	Home use to Enterprise-level	1.2.0.1 (May 27, 2008)
Customer Interaction Center	Windows 2003/XP	Closed Proprietary	SIP		IP PBX, ACD, IVR, Unified Messaging, Multi-media queueing, Skills-based routing	Enterprise and Contact (Call) Centers	2.4
Eyeball Server Suite	Red Hat Eneterprise 4 and Fedora Core 4 or higher	Proprietary	SIP, XMPP, STUN, TURN ICE NAT Traversal		IM server, NAT Traversal Server, SIP Proxy	Enterprise, Developer, Service Providers
CommuniGate Pro	Solaris, Linux, BSD, Mac OS X, Windows, AIX, HPUX	Freeware / Closed Proprietary	SIP, XMPP, XIMSS	TLS/SSL/HTTPS/SRTP/File Encryption/Cert Authority	VirtualPBX, Conferencing, ACD, Development environment, Flash UI	Carriers, IT-SP, Enterprise	5.1.x
ComunIP SIP Server	Linux, Microsoft Windows	Closed Proprietary	SIP, HTTP, Fast-CGI	TLS/SSL	General-purpose SIP server with a SOA architecture - uses Fast-CGI as backend processing (PHP as default language for customizing server-side applications), full web server integration (Apache, Lighttpd)	Application Service Provider Model to Carrier Grade, including support of SaaS delivery model	2.5.0 (July 31, 2007)
FreeSWITCH	Windows, Linux, BSD, Solaris	Open MPL free software	SIP, STUN, XMPP, Jabber, IAX	TLS, SRTP	Recording, Voicemail, Jabber IM, Google Talk, Proxy, Media gateway, Soft-PBX, IVR,	Large soft-switch users, home pbx users, softphone users	1.0.0 (May 26, 2008)
GNU Gatekeeper	Linux, Mac OS X, Windows XP/2000, FreeBSD	GPL Free software	H.323		Routing, Accounting, AUthorization		2.2.4
IXC Softswitch	FreeBSD	Closed/ Proprietary	H.323, SIP, MGCP, RADIUS		Includes integrated billing, codecs transcoding, protocol conversion, financial tools.	Carriers, ITSP, Enterprise, SMB. Services: origination, termination, DIDs, calling cards	4.4.x
miniSipServer	windows NT,2000,XP,2003	Closed Proprietary	SIP,SMB,SOHO		SIP server and SIP-PBX for the windows platform	Carriers, ITSP, Hosting Providers, Enterprise, SMB,SOHO,Individuals	2.2.8 SP1
Mysipswitch	Linux	BSD free software Open source	SIP, Ajax	SSL	SIP proxy server which allows the use of multiple SIP accounts with a single SIP login	Individuals	August 2007
Nortel's application Server 5200(mcs)	Linux	Proprietary	SIP , H.323	SSL encryption	multimedia conferencing, instant messaging (IM), presence and other collaboration tools	Unified Communication	5200
NetUP UTM billing software	Linux, FreeBSD, Solaris, Windows (NT, 2000, XP, 2003)	Closed Proprietary	H.323, SIP	RADIUS	Java-based multiplatform administration interface	VoIP providers and ISP	5.2.1-001
OpenSER	Linux, BSD, Solaris	GPL free software Open source	SIP	TLS	ENUM, IM, XMPP IM gateway, SMS gateway	Carrier, ITSP, Enterprise	1.2.2
PACER	Windows, Linux, Solaris, AIX, HPUX	Closed Proprietary		TLS, SSL, HTTPS	IVR, Voice broadcasting, Virtual PBX, ACD, XML Messaging, Development environment	Enterprise, Developer, Service Providers	12.1
pbxnsip	Windows, Linux	Closed Proprietary	SIP	TLS for signalling, SRTP and SDES for media and key exchange	IVR, Multicast Paging, Call Recording, Barge In, NAT-Traversal, Trunking, Cell Phone Support, Built-in mini-SBC, multiple-IP Address, Plug and Play, IM+Presence, IPv6	Appliances, Server	2.1 (release)
Solegy-OSS Desktop Dialer	Microsoft Windows	Freeware	SIP	Hash (CBCOM mode) Encryption	IM (SIP/SIMPLE or Jabber), NAT Traversal (STUN), multiple codecs	Service Providers, Developers	Beta (December 2006)
SIP Express Router (SER)	BSD, Linux, Solaris	GPL free software	SIP		SIP Registrar/Proxy, Authentication, Diameter, RADIUS, ENUM, and many others...	SIP Service Providers	2.0.0 Ottendorf
sipX ECS IP PBX	Linux	Open source L-GPL	Native SIP Call Control	HTTPS, TLS	Full redundancy (HA), plug & play management including phones and gateways, fully featured	Enterprises between 200 and 10,000 users, multi-site	3.6, Feb 12, 2007
SoftBX	Microsoft Windows XP/Server 2000/2003,Windows Mobile 6	Closed Proprietary	SIP, H.323, CAPI,		4-2000 users/per server, up to 512,000 ITSP platform, Voice Mail, Conference, Call Centre	ITSP Hosting Platforms, PBX replacement, Appliances	4.3.1001 (June 2007)
*starShop		Open source GPL	Based on Asterisk PBX		(PBX, not client)	Calling Shops and Internet cafes.	0.03 (19th February 2007)
SwyxWare	Microsoft Windows XP/2000/2003/Vista, Windows Mobile, Symbian, Black Berry	Closed Proprietary	SIP, H.323, CAPI		Too Many to List	Businesses from 5 users to 10000 Users	6.11 (19th February 2008)
TERAVoice Server	Windows 2000, XP, 2003, Vista	Freeware / Closed Proprietary	SIP, H.323, ISDN, analog	TLS	Soft-PBX, IVR, Voicemail, Voice Portal Server	2004 (17th of April 2005)
YATE	FreeBSD, Linux, Microsoft Windows, Solaris	GPL free software Open source	H.323, IAX, Jingle, SIP		SoftPBX, SIP SBC/Registrar/Proxy, H.323 Proxy, FAX, IVR, Conference, Music on Hold, Radius	Small office to carrier grade	1.2.0 (16th April 2007)
Program	Operating systems	Licence	Protocols/based upon/compatible with	Encryption	Other capabilities	Key and target markets	Latest release

See also

• Voice over IP
• Mobile VoIP
• Secure communication
• softphone
• Video conference