Editing Voice over IP (section)

===Milestones===
* 1966: [[Linear predictive coding]] (LPC) proposed by [[Fumitada Itakura]] of [[Nagoya University]] and Shuzo Saito of [[Nippon Telegraph and Telephone]] (NTT).<ref name="Gray"/>
* 1973: [[Packet telephony|Packet voice]] application by [[Danny Cohen (engineer)|Danny Cohen]].
* 1974: The [[Institute of Electrical and Electronics Engineers]] (IEEE) publishes a paper entitled "A Protocol for Packet Network Interconnection".<ref>{{cite journal|last=Cerf|first=V.|author2=Kahn, R. |title=A Protocol for Packet Network Intercommunication|journal=IEEE Transactions on Communications|date=May 1974|volume=22|issue=5|pages=637–648|doi=10.1109/TCOM.1974.1092259|url=http://www.cs.rice.edu/~eugeneng/teaching/f07/comp529/papers/ck74.pdf}}</ref>
* 1974: [[Network Voice Protocol]] (NVP) tested over [[ARPANET]] in August 1974, carrying barely intelligible 16{{nbsp}}kpbs [[CVSD]] encoded voice.<ref name="Gray"/>
* 1974: The first successful real-time conversation over ARPANET achieved using 2.4{{nbsp}}kpbs LPC, between Culler-Harrison Incorporated in [[Goleta, California]], and [[MIT Lincoln Laboratory]] in [[Lexington, Massachusetts]].<ref name="Gray"/>
* 1977: Danny Cohen and [[Jon Postel]] of the USC [[Information Sciences Institute]], and [[Vint Cerf]] of the Defense Advanced Research Projects Agency (DARPA), agree to separate IP from TCP, and create UDP for carrying real-time traffic.
* 1981: [[IPv4]] is described in RFC 791.
* 1985: The [[National Science Foundation]] commissions the creation of [[NSFNET]].<ref>{{cite web|url=https://www.nsf.gov/about/history/nsf0050/internet/launch.htm|title=The Launch of NSFNET|publisher=The National Science Foundation|access-date=January 21, 2009|archive-date=May 7, 2006|archive-url=https://web.archive.org/web/20060507225813/http://www.nsf.gov/about/history/nsf0050/internet/launch.htm|url-status=dead}}</ref>
* 1985: [[Code-excited linear prediction]] (CELP), a type of LPC algorithm, developed by [[Manfred R. Schroeder]] and [[Bishnu S. Atal]].<ref name="Schroeder"/>
* 1986: Proposals from various standards organizations{{specify|date=April 2012}} for [[VoATM|Voice over ATM]], in addition to commercial packet voice products from companies such as [[StrataCom]]
* 1991: Speak Freely, a voice-over-IP application, was released to the public domain.<ref name="B2C">{{cite web |last1=Dua |first1=Amit |title=VoIP Basics: Everything Beginners Should Know! |url=https://www.business2community.com/communications/voip-basics-everything-beginners-should-know-02422214 |website=business2community.com |date=July 29, 2021 |publisher=Business 2 Community |access-date=14 September 2021}}</ref><ref name="McCraw">{{cite web |last1=McCraw |first1=Corey |title=The History of VoIP Over the Last 55 Years (1966 to 2021) |url=https://fitsmallbusiness.com/history-of-voip/ |website=fitsmallbusiness.com |date=October 12, 2022 |publisher=Fits Small Business}}</ref>
* 1992: The Frame Relay Forum conducts development of standards for voice over [[Frame Relay]].
* 1992: [[InSoft Inc.]] announces and launches its desktop conferencing product Communique, which includes VoIP and video.<ref name="B2C" /><ref name="Inc1992">{{cite journal|author1=IDG Network World Inc|last2=Eckerson|first2=Wayne| title=Network World - Startup targets desktop Videoconferencing arena|journal=Network World|url=https://books.google.com/books?id=DhQEAAAAMBAJ&pg=PA39|access-date=February 10, 2012|date=September 21, 1992|publisher=IDG Network World Inc|pages=39–|issn=0887-7661}}</ref> The company is credited with developing the first generation of commercial, US-based VoIP, Internet media streaming and real-time Internet telephony/collaborative software and standards that would provide the basis for the Real Time Streaming Protocol (RTSP) standard.{{cn|date=July 2023}}
* 1993 Release of VocalChat, a commercial packet network PC voice communication software from [[VocalTec]].{{cn|reason=no occurrence of VocalChat at [[VocalTec]]|date=July 2023}}
* 1994: MTALK, a freeware LAN VoIP application for [[Linux]]<ref>{{cite web |url=http://sunsite.unc.edu/pub/Linux/apps/sound/talk/mtalk.README |publisher=Sunsite.edu |title=MTALK-Readme |access-date=April 29, 2012 |format=TXT}}</ref>
* 1995: 
**[[VocalTec]] releases ''Internet Phone'' commercial Internet phone software.<ref>{{cite web |url=http://blog.tmcnet.com/blog/tom-keating/docs/cti-buyers-guide-1996.pdf |publisher=Computer Telephony Interaction Magazine |title=Internet Phone Release 4 |last=Keating |first=Tom |access-date=November 7, 2007}}</ref><ref>{{cite web |url=http://www.ilocus.com/2007/07/the_10_that_established_voip_p_2.html |publisher=iLocus |title=The 10 that Established VOIP (Part 1: VocalTec) |access-date=January 21, 2009}}</ref>
** [[Intel]], [[Microsoft]] and [[Radvision]] initiated standardization activities for VoIP communications system.<ref>The free Library [http://www.thefreelibrary.com/RADVision+and+Intel+Target+Compatibility+Between+RADVision%27s+...-a019467970 RADVision and Intel Target Compatibility Between RADVision's H.323/320 Videoconferencing Gateway And Intel's Business Video Conferencing And TeamStation Products.] {{Webarchive|url=https://web.archive.org/web/20131030095918/http://www.thefreelibrary.com/RADVision+and+Intel+Target+Compatibility+Between+RADVision%27s+...-a019467970 |date=October 30, 2013 }} June 2, 1997 [http://www.radvision.com/Developer-Solutions/ VoiP Developer Solutions] {{Webarchive|url=https://web.archive.org/web/20110616001931/http://www.radvision.com/Developer-Solutions |date=June 16, 2011 }}</ref>
* 1996:
** [[ITU-T]] begins development of standards for the transmission and signaling of voice communications over Internet Protocol networks with the [[H.323]] standard.<ref>{{cite web |url=http://www.itu.int/rec/T-REC-H.323-199611-S/en |title=H.323 Visual telephone systems and equipment for local area networks which provide a non-guaranteed quality of service |publisher=ITU-T |access-date=January 21, 2009}}</ref>
** US telecommunications companies petition the US Congress to ban Internet phone technology.<ref>{{cite web|url=http://www.faqs.org/rfcs/rfc2235.html|title=RFC 2235|publisher=R. Zakon|access-date=January 21, 2009}}</ref>
** [[G.729]] speech codec introduced, using CELP (LPC) algorithm.<ref>International Telecommunication Union, Standardization Sector (ITU-T), Study Group 15 (1993-1996), ''Recommendation G.729'', March 1996.</ref>
* 1997: [[Level 3 Communications|Level 3]] began development of its first [[softswitch]], a term they coined in 1998.<ref name="ilocus softswitch">{{cite web|url=http://www.ilocus.com/2007/07/the_10_that_established_voip_p_1.html|title=The 10 that Established VOIP (Part 2: Level 3)|publisher=iLocus|date=July 13, 2007|access-date=November 7, 2007}}</ref>
* 1999:
** The [[Session Initiation Protocol]] (SIP) specification RFC 2543 is released.<ref>{{cite web|url=http://www.ietf.org/rfc/rfc2543.txt|title=RFC 2543, SIP: Session Initiation Protocol|publisher=Handley, Schulzrinne, Schooler, Rosenberg|access-date=January 21, 2009}}</ref>
** [[Mark Spencer (computer engineer)|Mark Spencer]] of [[Digium]] develops [[Asterisk (PBX)|Asterisk]], the first [[Open source software|open source]] [[private branch exchange]] (PBX) software.<ref>{{cite web|url=http://www.asterisk.org/about|title=What is Asterisk|publisher=Asterisk.org|access-date=January 21, 2009|archive-date=January 23, 2009|archive-url=https://web.archive.org/web/20090123154417/http://www.asterisk.org/about|url-status=dead}}</ref>
** A [[discrete cosine transform]] (DCT) variant called the [[modified discrete cosine transform]] (MDCT) is adopted for the [[Siren (codec)|Siren]] codec, used in the [[G.722.1]] [[wideband audio]] coding standard.<ref name="Hersent">{{cite book |last1=Hersent |first1=Olivier |last2=Petit |first2=Jean-Pierre |last3=Gurle |first3=David |title=Beyond VoIP Protocols: Understanding Voice Technology and Networking Techniques for IP Telephony |date=2005 |publisher=[[John Wiley & Sons]] |isbn=9780470023631 |page=55 |url=https://books.google.com/books?id=SMvNToRs-DgC&pg=PA55}}</ref><ref name="Lutzky">{{cite conference |last1=Lutzky |first1=Manfred |last2=Schuller |first2=Gerald |last3=Gayer |first3=Marc |last4=Krämer |first4=Ulrich |last5=Wabnik |first5=Stefan |title=A guideline to audio codec delay |url=https://www.iis.fraunhofer.de/content/dam/iis/de/doc/ame/conference/AES-116-Convention_guideline-to-audio-codec-delay_AES116.pdf |website=[[Fraunhofer IIS]] |conference=116th AES Convention |publisher=[[Audio Engineering Society]] |date=May 2004 |access-date=October 24, 2019}}</ref>
** The MDCT is adapted into the LD-MDCT algorithm, used in the [[AAC-LD]] standard.<ref name="Schnell">{{cite conference |last1=Schnell |first1=Markus |last2=Schmidt |first2=Markus |last3=Jander |first3=Manuel |last4=Albert |first4=Tobias |last5=Geiger |first5=Ralf |last6=Ruoppila |first6=Vesa |last7=Ekstrand|first7=Per |last8=Bernhard |first8=Grill |date=October 2008 |title=MPEG-4 Enhanced Low Delay AAC - A New Standard for High Quality Communication |url=https://www.iis.fraunhofer.de/content/dam/iis/de/doc/ame/conference/AES-125-Convention_AAC-ELD-NewStandardForHighQualityCommunication_AES7503.pdf |conference=125th AES Convention |publisher=[[Audio Engineering Society]] |access-date=October 20, 2019 |website=[[Fraunhofer IIS]]}}</ref>
* 2001: [[INOC-DBA]], the first inter-provider [[Session Initiation Protocol|SIP]] network is deployed; this is also the first voice network to reach all seven continents.<ref>{{cite book |last1=Stapleton-Gray |first1=Ross |title=Inter-Network Operations Center Dial-by-ASN (INOC-DBA), a Resource for the Network Operator Community |date=2009 |publisher=IEEE Computer Society Press |location=Los Alamitos |isbn=978-0-7695-3568-5}}</ref>
* 2003: [[Skype]] released in August 2003. This was the creation of Niklas Zennström and Janus Friis, in cooperation with four Estonian developers. It quickly became a popular program that helped democratize VoIP. 
* 2004: Early commercial VoIP service providers proliferate.{{cn|date=December 2024}}
* 2005: [[PhoneGnome]]  VoIP service is launched by TelEvolution, Inc. of California.<ref>{{cite news|url=https://www.nytimes.com/2007/08/02/technology/circuits/02pogue.html|title=State of the Art: Get Your Free Net Phone Calls Here|last=Pogue|first=David|date=August 2, 2007|work=The New York Times|accessdate=2009-01-20}}</ref>
* 2006: [[G.729.1]] wideband codec introduced, using MDCT and CELP (LPC) algorithms.<ref name="Nagireddi">{{cite book |last1=Nagireddi |first1=Sivannarayana |title=VoIP Voice and Fax Signal Processing |date=2008 |publisher=[[John Wiley & Sons]] |isbn=9780470377864 |page=69 |url=https://books.google.com/books?id=5AneeZFE71MC&pg=PA69}}</ref>
* 2007: VoIP device manufacturers and sellers boom in Asia, specifically in the Philippines where many families of overseas workers reside.<ref>{{Cite news|url=https://news.google.com/newspapers?nid=2479&dat=20070827&id=j1M1AAAAIBAJ&pg=1974,4860651|title=Prospects bright for voice calls over internet|last=Remo|first=Michelle V.|date=August 27, 2007|newspaper=Philippine Daily Inquirer|access-date=January 1, 2015}}</ref>
* 2009: [[SILK]] codec introduced, using LPC algorithm,<ref name="IETF79">[http://nagasaki.bogus.com/ietf79/ietf79-ch8-tue-noon.mp3 Audio-Mitschnitt] {{webarchive|url=https://web.archive.org/web/20130210051956/http://nagasaki.bogus.com/ietf79/ietf79-ch8-tue-noon.mp3 |date=February 10, 2013 }} vom Treffen der IETF-Codec-Arbeitsgruppe auf der Konferenz IETF79 in Peking, China mit einer Darstellung der grundlegenden Funktionsprinzipien durch Koen Vos (MP3, ~70&nbsp;MiB)</ref> and used for voice calling in [[Skype]].<ref>{{cite web |url=http://www.wirevolution.com/2009/01/13/skypes-new-super-wideband-codec/ |title=Skype's new super wideband codec |publisher=Wirevolution.com |date=January 13, 2009 |access-date=March 31, 2009}}</ref>
* 2010: [[Apple Inc.|Apple]] introduces [[FaceTime]], which uses the LD-MDCT-based AAC-LD codec.<ref name="AppleInsider standards 1">{{cite web|url=http://www.appleinsider.com/articles/10/06/08/inside_iphone_4_facetime_video_calling.html|date=June 8, 2010|access-date=June 9, 2010|title=Inside iPhone 4: FaceTime video calling|publisher=[[Apple community#AppleInsider|AppleInsider]]|author=Daniel Eran Dilger}}</ref>
* 2011:
** Rise of [[WebRTC]] technology which supports VoIP directly in browsers.
** [[CELT]] codec introduced, using MDCT algorithm.<ref name="presentation">[http://people.xiph.org/~greg/video/linux_conf_au_CELT_2.ogv Presentation of the CELT codec] {{Webarchive|url=https://web.archive.org/web/20110807182250/http://people.xiph.org/~greg/video/linux_conf_au_CELT_2.ogv |date=August 7, 2011 }} by Timothy B. Terriberry (65 minutes of video, see also [http://www.celt-codec.org/presentations/misc/lca-celt.pdf presentation slides] {{Webarchive|url=https://web.archive.org/web/20110810032741/http://www.celt-codec.org/presentations/misc/lca-celt.pdf |date=August 10, 2011 }} in PDF)</ref>
* 2012: [[Opus (audio format)|Opus]] codec introduced, using MDCT and LPC algorithms.<ref name="Valin">{{cite conference|last1=Valin|first1=Jean-Marc|last2=Maxwell|first2=Gregory|last3=Terriberry|first3=Timothy B.|last4=Vos|first4=Koen|date=October 2013|title=High-Quality, Low-Delay Music Coding in the Opus Codec|conference=135th AES Convention|publisher=[[Audio Engineering Society]]|arxiv=1602.04845}}</ref>