OpenFlow allows Google to calmly face the rapidly increasing demand for network

According to Arbor network coverage (Note 1), in 2007, the network traffic generated by Google in the proportion of global Internet traffic is only about 1%, while in 2010 the proportion of Google's been nearly 7%. The face of the popularity of Internet and the rapid growth of bandwidth requirements, Google needs to find the brunt of solutions to cope with today's Internet traffic and the engineering management.


After understanding the advantages of the central project management (Centralized traffic engineering), as well as software-defined network (Software Defined Networking, referred SDN), Google began to gradually replace the existing network hardware to OpenFlow architecture in 2012. Google's wide area network (WAN) system consists of two main backbone network, users face major backbone network carries user traffic is called I-Scale, as well as various data centers Google series (Data Center ) system for internal transport network called G-Scale. There's great differences between two main networks' demand and traffic characteristics, Google decided to use SDN (the core of Open Flow) in G-Scale network deployment.

For G-scale network, Google uses a three-stage implementation of OpenFlow network architecture, the first phase to start in spring 2010, the network architecture in two batches conversion, successive test and upgrade to OpenFlow architecture; until the middle of 2011 the second stages, Google started more based (Software Defined Networking), and the introduction of more network traffic to test new OpenFlow network architecture; until the first half of 2012, Google has all the backbone network data centers set up in accordance with OpenFlow network, while the network traffic to migrate to the central project management to control traffic. External replication scheduler (copy scheduler) has also been interacting with OpenFlow controller and complete large data replication (large data copies) schedule.

After gradually into the OpenFlow architecture, Google's information transmission flow constantly being expanded and optimized.

After Google implement software-defined network (SDN), they never have packet loss (packet loss) and attenuation capacity (capacity degradation) problems, and also to maintain a simple and high-fidelity test environment which can be simulated in the entire backbone network operation to better enjoy hitless software upgrades, and most of the software upgrade also involves updating the switch without hardware.

And although the current running time is still too short to quantify the benefits of converting to OpenFlow system, but Google has felt the OpenFlow enhance the stability of the overall network environment, but also to foresee the possibility of a more substantial OpenFlow optimize network traffic, especially point to point transmission, can be more flexible management.

Google's upgrades confirmed whether OpenFlow or SDN (Software Defined Networking) can be implemented under existing enterprise network environment. OpenFlow can not only simplify network management, but also make the large number of feature deployment become possible.