Danny Cohen

lore

networking

The engineer who put real-time voice and video onto a packet network in 1973, by adapting a flight simulator.

The ARPANET was built to move files and messages, where arriving late is an inconvenience. He adapted a visual flight simulator to run across it, which requires the opposite property: a packet that arrives late is worse than one that never arrives at all. That is the first application of packet switching to real time, and every argument since about jitter buffers, quality of service and whether the internet can carry a phone call descends from someone attaching a simulator to a research network to see what would happen.

Also known as: cohen, network voice protocol, packet voice

Sources

Danny Cohen was the first to implement packet video and packet voice, the Network Voice Protocol, when he adapted the visual flight simulator to run over the ARPANET in 1973; it was the first application of packet switching to real-time applications

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