History of Voip

History

The early developments of packet network designs by Paul Baran and other researchers were motivated by a desire for a higher degree of circuit redundancy and network avalability in face of infrastructure failures than was possible in the circuit-switched networks in telecommunications in the mid-twentieth century. In 1973, Danny Cohen first demonstrated a form of packet voice as part of a flight simulator application, which operated across the early ARPANET. In the following time span of about two decades, various forms of packet telephony were developed and industry interest groups formed to support the new technologies. Following the termination of the ARPANET project, and expansion of the Internet for commercial traffic, IP telephony became an established area of interest in commercial labs of the major IT concerns, such Microsoft and Intel, and open-source software, such as VocalTec, became available by the mid-1990s. By the late 1990s, the first softswitches became available, and new protocols, such as H.323, the Media Gateway Control Protocol (MGCP) and the Session Initiation Protocol (SIP) gained widespread attention. In the early 2000s, the proliferation of high-bandwidth always-on Internet connections to residential dwellings and businesses, spawned an industry of Internet telephony service providers (ITSPs). The development of open-source telephony software, such as Asterisk PBX, fueled widespread interest and entrepreneurship in voice-over-IP services, applying new Internet technology paradigms, such as cloud services to telephony.

Milestones

• 1973: Packet voice application by Danny Cohen

• 1974: The Institute of Electrical and Electronic Engineers (IEEE) publishes a paper entitled "A Protocol for Packet Network Interconnection".

• 1974: Network Voice Protocol (NVP) tested over ARPANET in August 1974, carrying 16k CVSD encoded voice.

• 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.

• 1986: Proposals from various standards organizations for Voice over ATM, in addition to commercial packet voice products from companies such as StrataCom

• 1991: First Voice-over-IP application, Speak Freely, is released into the public domain. It was originally written by John Walker and further developed by Brian C. Wiles.

• 1992: The Frame Relay Forum conducts development of standards for Voice over Frame Relay.

• 1994: MTALK, a freeware VoIP application for Linux

• 1995: VocalTec releases the first commercial Internet phone software.

• Beginning in 1995, Intel, Microsoft and Radvision initiated standardization activities for VoIP communications system.

• 1996:

• ITU-T begins development of standards for the transmission and signaling of voice communications over Internet Protocol networks with the H.323 standard.

• US telecommunication companies petition the US Congress to ban Internet phone technology.

• 1997: Level 3 began development of its first softswitch, a term they coined in 1998.

• 1999:

• The Session Initiation Protocol (SIP) specification RFC 2543 is released.

• Mark Spencer of Digium develops the first open source private branch exchange (PBX) software (Asterisk).

• 2004: Commercial VoIP service providers proliferate.

• 2007: VOIP device manufacturers and sellers boom in Asia, specifically in the Philippines where many families of overseas workers reside.

• 2011: Raise of WebRTC technology which allows VoIP directly in browsers

• 2015: Trend of using VoIP services in cloud: PBXes and contact centers, it means higher requirements to IP network to achieve good quality of service and reliability