A Brief Prehistory of Voice over IP parts 1 & 2

Google Tech Talk August 10 & 11, 2010


Presented by Danny Cohen and Stephen Casner. This talk explores the development of interactive packet voice beginning in 1974 with experiments over the ARPAnet in the NSC (Network Speech/Secure Communication) program sponsored by ARPA, initiated by Bob Kahn. One highlight will be the showing of a movie made in 1978 to demonstrate a multi-party teleconference over the packet network, including one participant interfaced from a telephone. The talk will be presented in two sessions (two days), with the movie shown at the start of the second session. Part one covers concepts and lessons from this project: * A 1971 realtime distributed flight simulation that sparked the idea * Understanding real-time vs non-real-time communication * Digital speech and the need to compress it (PCM, DPCM, CVSD, LPC/LPC10) * Network Voice Protocol (NVP) over the ARPAnet, type0/type3 packets * The birth of the Internet with TCP * Separating IP from TCP and adding UDP * Building NVP-II on top of IP * Adding packet video (DCT based compression) Part two emphasizes the development of the voice protocols: * Introducing and showing the teleconferencing movie from 1978 * Advances in equipment and function at the end of NSC in 1982 * Progress stalled, waiting to low-cost vocoding * Development of IP Multicast and the MBone * Evolution from NVP to RTP, and RTP design philosophy * Conferencing control protocols * More recent history of VoIP Speaker Info: Danny

VOIPO residential phone service for $8.25 per month