Takayasu's team has been trying to understand what happens when the junctions are so jammed that the system begins to throw packets away. The analogy she chose for Internet traffic was infectious disease. Her slide showed a rank of schoolchildren sitting at desks. Internet traffic behaves very like an infectious disease viewed from the vantage point of the organism. So can a router.
Many models having different evolution properties converge to the contact model.
Going beyond modeling, Takayasu's team used the Internet as an experimental organism, sending packets to and from the most congested points, predicting what would happen at times of high congestion and measuring the actual behavior of the packets. The system is very elastic. The Internet might never have survived at all, added the final speaker, Deborah Estrin of the University of Southern California, if it had been built as a rigid and stable steady-state entity. Mathematicians may not yet understand the Internet's behavior, but biologists can certainly recognize some of its qualities. The net is a good place for keeping those photographs of nature and other things within one's own back yard.