An End to the Middle

The last fifteen years has seen a vast proliferation of middleboxes to solve all manner of persistent limitations in the Internet protocol suite. Examples include firewalls, NATs, load balancers, traffic shapers, deep packet intrusion detection, virtual private networks, network monitors, transparent web caches, content delivery networks, and the list goes on and on. However, most smaller networks in homes, small businesses and the developing world are left without this level of support. Further, the management burden and limitations of middleboxes are apparent even in enterprise networks. We argue for a shift from using proprietary middle-box harware as the dominant tool for managing networks toward using open software running on end hosts. We show that functionality that seemingly must be in the network, such as NATs and traffic prioritization, can be more cheaply, flexibly, and securely provided by distributed software running on end hosts, working in concert with vastly simplified physical network hardware.