Tuesday, April 4, 2017

Google Builds Expresso SDN for Public Internet

"SDN is how we do networking… so what’s next?" asked Amin Vahdat, Fellow and Technical Lead for Networking at Google, at the opening of his keynote address at the Open Networking Summit in Santa Clara, California.


Google has been using SDN for years to manage its private B4 global WAN (interconnects data centers) and its Jupiter networks (inside its data centers, which have up to 100,000 servers and up to 1 Pb/s of aggregate bandwidth). Traffic on its private networks exceeds that on its public Internet backbone, and the growth rate is faster too. Google also relies on its Andromeda network functions virtualization platform as one of its pillars of SDN.

Google's next step is to introduce "Expresso" SDN for its public Internet backbone.  Expresson has been running on the Google network for the past two years and is currently routing about 20% of traffic to the Internet.

Essentially, Google Expresso SDN Peering takes a metro and global view across many routers to find optimal route for traffic delivery.  Whereas traditional, router-centric protocols take a connectivity-first approach with only local information, Vahdat said Expresso is able to optimize route selection in real-time by leveraging application signals across the metro or global infrastructure. One effect is to remove the logic and control of traffic management from individual boxes and make it network-centric.

Here is an architectural view of Google Expresso SDN:



Expresso sets the stage for the next decade in networking, said Vahdat, where the Internet must deliver improvements in scale, agility, jitter, isolation and availability. Google sees each of these attributes as necessary for the next wave of serverless computing.