Amin Vahdat, fellow and technical lead for networking at Google, took a look back in order to show the way forward for the search engine giant during his keynote at today's Open Networking Summit.

Vahdat described how Google looked to software-defined networking (SDN) industry before the technology even received its moniker. (He might as well have put on hipster glasses and said, "We've been SDN-ing before SDN-ing was even mainstream enough for its own conference!")

Vahdat has discussed Google's SDN usage at previous ONSs, talking about B4, Google's SD-WAN, and Andromeda, its network virtualization service. This time, he gave us a look into what really makes Google tick — the innards of its data center network.

Years ago, it became clear that traditional network architectures could not scale at the necessary pace for Google's data center. "We couldn't even buy a data center system that met the needs of the distributed systems," said Vahdat. "They just couldn't keep up with the bandwidth demands in the data center."

For Google, scalability is inherent to the company's viability — it couldn't afford to have network size be limited by the largest size of purchasable routers. What it did next paved the road for SDN within the company.

Google looked to Clos topologies, merchant silicon, and centralized control (the mainstay of SDN) as inspiration for its data center networking model. In doing so, it found new life in campus aggregation and WAN. B4 and Andromeda were built from the data center network model Google spawned nearly a decade ago, says Vahdat.

With data-center traffic having grown 50 times between 2007 and 2014, Google still considers scalability crucial. Other scale statistics Vahdat discussed were so large that even ONS Chair Guru Parulkar admitted to not truly understanding their expanse — for example, Jupiter, the fifth and current generation of Google's data-center architecture, can produce 1.3 petabits per second per cluster.

"Computing is at a crossroads. At Google, we are particularly interested in networking, as it's going to change what computing means," Vahdat says.

Vahdat said Moore's Law, the observation that the number of transistors per square inch on integrated circuits doubles each year, is coming to an end and fast. "It's going to be here soon and we have to change how we think about computing," he says. "We can't continue to rip out our network and replace it to keep up with bandwidth needs."

With SDN, Google is able to meet this growing demand. Its data center network infrastructure can support scale, performance, and availability — and developers now have a chance to tinker with it in the Google Cloud Platform, Vahdat said.

Follow the ongoing coverage of the Open Networking Summit 2015 here, and you can watch a live stream of the full event here.