VoIP (Voice over Internet Protocol) is a way of turning an internet-connected device into a telephone. Most applications use [[SIP]] to make calls - this is the foremost industry standard, although [[http://en.wikipedia.org/wiki/XMPP|XMPP (also known as Jabber)]] is also extremely popular. === SIP or XMPP (Jabber)? === SIP has slightly more emphasis on voice, video and corporate telephony, whereas XMPP originated as a solution for chat and messaging but it's extensible nature allows it to support voice and video. Many people use both SIP and XMPP from a single client. == VoIP and messaging on the Ubuntu desktop == Ubuntu's principal application for this is called [[Empathy]], and provides many features in addition to simple voice, such as video chat. There are several other end-user applications which you may also consider: * [[Jitsi]] is the most extensive and versatile open source VoIP and messaging solution * [[Ekiga]] was previously the default VoIP solution in Ubuntu * [[KPhone]] the definitive KDE desktop voice application * [[Twinkle]] looks good with KDE desktop; no video chat * [[Qutecom]] also fits KDE desktop better; successor to wengophone, but no tie-in to one provider == Ubuntu as a VoIP / Real-time communication (RTC) server == * To start quickly, the [[http://www.rtcquickstart.org|Real-time communications (RTC) quick start guide]] is highly recommended * [[repro]] is a SIP proxy server supporting federated VoIP between [[Ubuntu]] servers and other external servers on the public internet * [[Asterisk]] an advanced user to professional grade telephony server which can route calls between various sources Please also see the Debian wiki about [[http://wiki.debian.org/UnifiedCommunications|Unified Communications]] as many of the Debian solutions are available on Ubuntu. == Skype == It was previously possible to install Skype, but there are both technical and ethical reasons why you should not (see [[SkypeEthics]] for more): * unethical business practices - disclosure of IM conversations to the Chinese government leading to imprisonment of Chinese pro-democracy campaigners. * closed-protocol - Skype users can only call Skype users; SIP users, however, can call anybody on any network. * closed-source - What's Skype doing to your computer? Who knows? Is it secure? Who knows? All the alternative applications above are open source. * privacy and advertising: Skype's new owners, Microsoft, are scanning the content of Skype calls and building up a huge database profiling all their users to help in more insidious forms of advertising = External Links = * [[http://dione.no-ip.org/wordpress/computing/introduction-to-sip/|Introduction to SIP]]