Lost in Network Address Translation
Vladimir Andrei Olteanu, Felipe Huici, Costin Raiciu · 2015
To understand whether the promise of Network Function Virtualization can be accomplished in practice, we set out to create a software version of the simplest middlebox that keeps per flow state: the NAT. While there is a lot of literature in the wide area of SDN in general and in scaling middleboxes, we find that by aiming to create a NAT good enough to compete with hardware appliances requires a lot more care than we had thought when we started our work. In particular, limitations of OpenFlow switches force us to rethink load balancing in a way that does not involve the centralized controller at all. The result is a solution that can sustain, on six low-end commodity boxes, a throughput of 40Gbps with 64B packets, on par with industrial offerings but at a third of the cost.