David Wetherall, David Tennenhouse
Network programmability has metamorphosed over the past twenty years from the controversial research vision of active networks, through PlanetLab, to the juggernaut of SDN and OpenFlow that has swept industry. Now PISA switches are emerging with support for protocol-independent reconfigurability. We reflect on how net- work architecture has evolved along a different path than we had foreseen to arrive at a place that is not so different than we and other researchers had hoped and imagined.