It was one of the pioneering networks experimenting with the concept of packet switching and, unlike the ARPANET, was explicitly designed to facilitate internetworking.
The basic packet transmission like function, named CIGALE, was novel; it provided an unreliable datagram service (the word was coined by Louis Pouzin by combining data and telegram).
I thought one was enough.”The CIGALE network featured a distance vector routing protocol, and allowed experimentation with various metrics.
The transport protocol was able to deal with out-of-order and unreliable delivery of datagrams, using the now-standard mechanisms of end-end acknowledgments and timeouts; it also featured sliding windows and end-to-end flow control.
The academic debates between datagram and virtual circuit networks continued for some time, but were eventually cut short by bureaucratic decisions.
Data transmission was a state monopoly in France at the time, and IRIA needed a special dispensation to run the CYCLADES network.
[8] The most important legacy of CYCLADES was in showing that moving the responsibility for reliability into the hosts was workable, and produced a well-functioning service network.
Hubert Zimmermann used his experience in CYCLADES to influence the design of the OSI model, which is still a common pedagogical tool.
Gérard Le Lann worked with Vint Cerf and Bob Kahn to incorporate concepts from the CYCLADES project into the original design of the Transmission Control Program.