The Achilles heel of the otherwise extremely successful Internet infrastructure has been its rigidity, which has primarily stemmed from the ossification of shortest-path routing in the basic architecture. The increasing effect of this rigidity of the current Internet infrastructure, coupled with the popular belief that basic IP routing cannot be changed, has led to many companies and researchers turn to infrastructure-based overlay networks to meet specific application requirements. These overlay networks, however, are mostly independent efforts, sharing nothing but the underlying IP infrastructure. We first try to argue for the need for reversing this trend, and in the process propose a panacea -- a global shared overlay infrastructure.

We envision that a single set of overlay infrastructure nodes, supporting a few simple primitives, would allow end-hosts to choose routes over the infrastructure, thus enabing the end-hosts to achieve various services they desire. The foremost challenge we face here is to design flexible primitives that the infrastructure should export. The second requirement is to support a mechanism that allows end-hosts to find paths based on application-sensitive metrics. We achieve this by building a NEtwork Weather Service (NEWS) that measures performance characteristics of the infrastructure. The final requirement, also of paramount importance, is to make sure that the infrastructure is DoS resistant. Thus, end-hosts, by querying the NEWS nodes build application-specific services using the routing primitives that the infrastructure exports. Experiments using an initial deployment of NEWS over PlanetLab have shown that our techniques perform very well.