This paper uses a variety of mathematical models to explore some of the consequences of rapidly growing communications capacity for the evolution of the Internet. It argues that queueing delays may become small in comparison with propagation delays, and that di¬erentiation between tra¯c classes within the network may become redundant. Instead, a simple packet network may be able to support an arbitrarily di¬erentiated and constantly evolving set of services, by conveying information on incipient congestion to intelligent end-nodes, which themselves determine what should be their demands on the packet network.