Software-defined internet architecture
Barath Raghavan, Martín Casado, Teemu Koponen, Sylvia Ratnasamy, Ali Ghodsi, Scott J. Shenker · 2012
In current networks, a domain can effectively run a network architecture only if it is explicitly supported by the network infrastructure. This coupling between architecture and infrastructure means that any significant architectural change involves sizable costs for vendors (for development) and network operators (for deployment), creating a significant barrier to architectural evolution.