So you cut over this new network but didn't take down the old one; what do you estimate the new network is accounting for in terms of your total inter-data center load?
Over a two-year period we have been shifting, incrementally, over to the new network, and it's fair to say that a substantial majority of the traffic is now on the new network.
Was OpenFlow fully baked as you were implementing it, or did you have to improvise a lot?
We had to improvise. OpenFlow is standardizing the interface, and I think this is very important for the community. So what OpenFlow and software-defined networking really enables us to do is separate the evolution path for hardware and software. In other words, you can get the hardware that meets your needs and separate that from the software that meets your needs for a particular deployment. Historically, those two things have been wedded together.
BEGINNINGS: OpenFlow and SDN: Networking's future?
So from an OpenFlow standardization perspective, it's very, very important to have hardware that can interoperate with a variety of software controllers. From our side, since we're building our own hardware, that was less important. But we definitely had to improvise, and certainly the OpenFlow standard has evolved and we've had to be nimble with that internally.
Did you have any setbacks of note?
I think Urs Hölzle [senior vice president of technical infrastructure and Google Fellow] said it best when he said it actually has gone more smoothly than he expected with less down time. The main issues we ran into from an OpenFlow perspective is the first version doesn't fully allow you to take advantage of all of the hardware capabilities in modern switch silicon in an easy way. That's not to say it's not possible, it's just not easy. So we have to do some work to get around some of those mismatches and, if you will, interface them. But this is now substantially improved from the OpenFlow standard perspective.
How far away is OpenFlow from being fully baked?
I think it's going to be a multi-year process, but the message we want to send is it's at a point now where it's incredibly useful and can deliver substantial benefits in a variety of settings.
Given the advantages, do you expect to see service providers move to OpenFlow?
Well, we certainly hope so. What we're hearing from the large service providers is that it is difficult to scale and make money. With OpenFlow I think we've demonstrated how to make your network much, much more efficient.
So you've been at this for a few years already; what are the next steps?