On November 22, 1977, DARPA conducted the world's first field demonstration of internetworking across three distinct physical networks: the Packet Radio Network (PRNET), the Satellite Network (SATNET), and the ARPANET.
Engineers from SRI International, Bolt Beranek and Newman (BBN), and University College London configured a mobile research van traveling along California's Bayshore Freeway to transmit data over packet radio signals. The data stream was routed through an SRI gateway onto the terrestrial ARPANET, sent via satellite ground stations in West Virginia to SATNET over the Atlantic, routed to Sweden and Great Britain, and finally sent back across the Atlantic to California.
The experimental packets traveled over 94,000 miles across radio waves, satellite signals, and underground copper lines without losing a single bit of information. This historical test confirmed that TCP could successfully maintain reliable host-to-host transmission across radically different communication environments.
Why it matters
This demonstration proved that internetworking was not just a theoretical concept, but a functioning technology capable of spanning global distances and mixing radically different hardware media—including mobile radio, satellite, and land cables—into a unified network of networks.
Interesting fact
Despite traveling through radio waves, satellite hops, and transatlantic cables over a distance of 94,000 miles, the data returned to its destination host in California completely uncorrupted.
People
- Bob KahnDARPA Information Processing Techniques Office Director
- Vint CerfDARPA Program Manager
- Don NielsonSRI International Project Director
- Peter KirsteinUniversity College London Research Lead
Quotes
"We had data going through radio to satellite to land lines and back, and it worked flawlessly across thousands of miles."
Location
SRI International · Menlo Park · United States
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