A Peek At Google's Software-Defined Network

CowboyRobot writes "At the recent 2013 Open Networking Summit, Google Distinguished Engineer Amin Vahdat presented 'SDN@Google: Why and How', in which he described Google's 'B4' SDN network, one of the few actual implementations of software-defined networking. Google has deployed sets of Network Controller Servers (NCSs) alongside the switches, which run an OpenFlow agent with a 'thin level of control with all of the real smarts running on a set of controllers on an external server but still co-located.' By using SDN, Google hopes to increase efficiency and reduce cost. Unlike computation and storage, which benefit from an economy of scale, Google's network is getting much more expensive each year."

Comments

Hype

[Anonymous Coward]

SDN is hype, just like CLOUD.

Re:centralized = fault-tolerant?

[bill_mcgonigle]

With a centralised controller the problem is much easier. One program running on one CPU decides how to reconfigure the network. This can be faster and possibly find a better solution.

I can see how centralizing the control can be easier. But if the history of Internet networking has taught us anything, we should expect somebody to come up with a more clever distributed algorithm (perhaps building on OpenFlow) that will make SDN's a footnote in history while the problem gets distributed out to the network nodes again, making it more resilient.

That's not to say that trading off resiliency for performance today isn't worthwhile in some applications.