History

* 1974 - The Institute of Electrical and Electronic Engineers (IEEE) published a paper entitled "A Protocol for Packet Network Interconnection."[2]
* 1981 - IPv4 is described in RFC-791[3]
* 1985 – The National Science Foundation commissions the creation of NSFNET[4]
* 1995 – VocalTec releases the first commercial Internet phone software[5][6].
* 1996 -
o ITU-T begins the standardization of VoIP initially with the H.323 standard[7]
o US telecommunication companies ask the US Congress to ban Internet phone technology[8].
* 1997 - Level 3 began development of its first softswitch (a term they coined in 1998)[9]
* 1999 -
o The Session Initiation Protocol (SIP) specification RFC-2543 was released[10]
o The first open source SIP PBX (Asterisk) is created by Mark Spencer of Digium[11]
* 2004 - Commercial VoIP service providers proliferate[12]