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Important progress has been made in the fusion of cloud development and deployment -- what the industry calls DevOps. There are also important developments in the area of cloud networking, another topic I've written about recently. One indication of a unified approach to these critical issues was announced this week by Big Switch Networks, a software-defined networking (SDN) vendor. I'll talk about Big Switch's announcement regarding its Open SDN architecture, but first I need to summarize why it's important.
The cloud has preoccupied nearly everyone, but not much attention has been focused on how the cloud changes the model of network services. In the past, we obtained services by linking over the Internet to a URL that represented the capability or information we wanted. On the surface, the cloud networking model doesn't seem too different. We have stuff hosted "in the cloud," and the stuff is still accessed via a URL. Sure, there are issues associated with the way a dynamic resource is mapped to a URL. Hey, it's not rocket science, but look deeper and you see more differences -- perhaps enough to create a revolution.
In a cloud future, users' needs are more dynamic too. Imagine a Siri-like process that acts as a front-end for a dynamic resource pool and you get a glimpse of what's coming. The user requests data via an agent in the cloud, and the agent marshals all sorts of processing power and information to fulfill it. That information isn't delivered directly to the user -- but through the agent -- and the information paths are internal to the cloud (and not external for the user). That's cloud networking: the separation of cloud-flow from user-flow.
Content delivery already has a similar model; a content delivery network (CDN) is a set of caches (pushed increasingly closer the user) and an interior network that delivers data to those caches. Users connect not with distant content hosts but to local cache points. Inside the CDN, there are a limited number of (you've got it!) flows.
OpenFlow: The answer to cloud networking?
Enter another kind of flow: OpenFlow. OpenFlow is an explicit-connection model of networking where flows are authorized -- not automatic. It doesn't scale for the whole the Internet, but OpenFlow is perfect for a cloud. Even virtual private networks (VPNs) likely will fit in the OpenFlow model, and data center networks darn sure do. The cloud validates OpenFlow, provided that you can get an OpenFlow cloud model built in the real world.
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Architecturally, it's not hard to build this utopian model of linking applications to explicit network flows. A switch controller simply creates forwarding rules -- that's the OpenFlow model. In practice, though, you need to worry about things like how you manage persistent flows, how you create a VPN or virtual private LAN service (VPLS) and how your applications actually drive policies. There's a lot of stuff that has to be added to OpenFlow standard to create a production-worthy, flow-based network. We must start by looking the problem at the ecosystem level, from apps to flows.
Some of the answers could come from cloud networking, which must contend with the fact that cloud resources have addresses but applications can't be addressed -- at least until they're assigned to resources. A virtualization element is needed here that OpenStack players, for example, have recognized and are attempting to address through work like Melange and Donabe. These projects link applications and provisioning, but we need to link those to network flows.
Big Switch makes big cloud networking play
Big Switch is an early, startup player in OpenFlow. We wrote about the company in our Netwatcher OpenFlow feature in October 2011 when it had only an OpenFlow controller play. What it's doing now is defining a broader ecosystem with its Open SDN architecture -- open standards, open application programming interfaces (APIs) and open source. Big Switch's business model, like that of other vendors that work with open source projects, is to provide professional services and a hardened version of some software for commercial application.
Big Switch may be a tiny magician that has pulled a 900-pound gorilla out of a hat instead of a fuzzy bunny.
The Open SDN model is a flow from application to switch that focuses on how you build a practical flow network and sustain its operation. It handles essential cloud networking features like multi-tenancy, on-demand or policy-based flows. And best of all, it handles integration with OpenStack.
While Big Switch isn't asserting direct compatibility with all of the various OpenStack network-related projects, it is involved with the Quantum project and has a submission there. Quantum is an OpenStack offshoot that focuses on network services -- playing to OpenStack's inherent vision that the network is also a resource in the cloud -- and it could be linked to Melange and Donabe for a more cohesive DevOps strategy. This arguably makes Big Switch the first player to link all the way from the cloud-resource vision down to an OpenFlow switch.
My view is that all of this is really just the tip of a very large iceberg regarding the future of clouds, networks and Network as a Service (NaaS). If you can do cloud networking, then you can do everything that's part of the cloud. And since the cloud is the abstraction of computing and network-delivered services for the future, you can do what the future needs.
It would be easy to get overly excited about the pieces that make up networks of the future, but we can't build them by thinking at the pieces level, which is why there's a real need for a top-down model that links apps to clouds to flows. We now have at least one such model.
One model usually doesn't make a market, however. We're likely to see a lot more action in this space. There are rumors now that Cisco Systems is mulling an OpenFlow play, but I think that's likely to materialize as a hardware product. The stuff that acts as the bridge between the application, the cloud, the resource control, addressing and information flows could be really critical as a competitive point for vendors in the networking space -- even for next-generation OSS/BSS development. Thus Big Switch may be a tiny magician that has pulled a 900-pound gorilla out of a hat instead of a fuzzy bunny. Can it control its own fate here? We'll see.
About the author: Tom Nolle is president of CIMI Corporation, a strategic consulting firm specializing in telecommunications and data communications since 1982. He is the publisher of Netwatcher, a journal addressing advanced telecommunications strategy issues. Check out his blog for the latest in communications business and technology development.