OpenDaylight: A big step toward the software-defined data center

Manual hardware configuration is the scourge of the modern data center. Server virtualization and pooled storage have gone a long way toward making infrastructure configurable on the fly via software, but the third leg of the stool, networking, has lagged behind with fragmented technology and standards.

The OpenDaylight Project — a new open source project hosted by the Linux Foundation featuring every major networking player — promises to move the ball forward for SDN (software-defined networking). Rather than hammer out new standards, the project aims to produce an extensible, open source, virtual networking platform atop such existing standards as OpenFlow, which provides a universal interface through which either virtual or physical switches can be controlled via software.

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The approach of OpenDaylight is similar to that of Hadoop or OpenStack, where industry players come together to develop core open source bits collaboratively, around which participants can add unique value. That roughly describes the Linux model as well, which may help explain why the Linux Foundation is hosting OpenDaylight.

“The Linux Foundation was contacted based on our experience and understanding of how to structure and set up an open community that can foster innovation,” said Jim Zemlin, executive director of the Linux Foundation, in an embargoed conference call last week. He added that OpenDaylight, which will be written in Java, will be available under the Eclipse Public License.

Collaboration or controversy?

It must be said that the politics of the OpenDaylight Project are mind-boggling. Cisco is on board despite the fact that SDN is widely seen as a threat to the company’s dominant position — because, when the network is virtualized, switch hardware becomes more commoditized. A cynic might be forgiven for wondering whether Cisco is there to rein things in rather than accelerate development.

Along with Cisco, the cavalcade of coopetition includes Arista Networks, Big Switch Networks, Brocade, Citrix, Dell, Ericsson, Fujitsu, HP, IBM, Intel, Juniper Networks, Microsoft, NEC, Nuage Networks, PLUMgrid, Red Hat, and VMware. BigSwitch, perhaps the highest-profile SDN upstart, is planning to donate a big chunk of its Open SDN Suite, including controller code and distributed virtual routing service applications. Although VMware has signed on, it’s unclear how the proprietary technology developed by Nicira, the SDN startup acquired for $1.2 billion by VMware last summer, will fit in.

Another question is how OpenDaylight will affect other projects. Some have voiced frustration over the Open Network Foundation’s stewardship of the OpenFlow, so OpenDaylight could be a way to work around that organization. Also, OSI president and InfoWorld contributor Simon Phipps wonders why Project Crossbow, an open source network virtualization technology built into Solaris, appears to have no role in OpenDaylight. You can be sure many more questions will emerge in the coming days and weeks.

The architecture of OpenDaylight

Zemlin described OpenDaylight as an extensible collection of technologies. “This project will focus on software and will deliver several components: an SDN controller, protocol plug-ins, applications, virtual overlay network, and the architectural and the programmatic interfaces that tie those things together.”

This list is consistent with the basic premise of SDN, where the control and data planes are separated, with a central controller orchestrating the data flows of many physical or virtual switches (the latter running on generic server hardware). OpenFlow currently provides the only standardized interface supported by many switch vendors, but OpenDaylight also plans to support other standards as well as proprietary interfaces as the project evolves.

More exciting are the “northbound” REST APIs to the controller, atop which developers will be able to build new types of applications that run on the network itself for specialized security, network management, and so on. In support of this, Cisco is contributing an application framework, while Citrix is throwing in “an application controller that integrates Layer 4-7 network services for enabling application awareness and comprehensive control.”

Although the embargoed OpenDaylight announcement was somewhat short on detail, a couple of quick conclusions can be drawn. One is that — on the model of Hadoop, Linux, and OpenStack — the future is now being hashed out in open source bits rather than standards committees. The rise in the importance of open source in the industry is simply stunning, with OpenDaylight serving as the latest confirmation.

More obviously, the amazing breadth of support for OpenDaylight signals new momentum for SDN. To carve up data center resources with the flexibility necessary for a cloud-enabled world where many tenants must coexist, the network needs to have the same software manageability as the rest of the infrastructure. OpenDaylight leaves no doubt the industry recognizes that need.

If the OpenDaylight Project can avoid getting bogged down in vendor politics, it could complete the last mile to the software defined data center in an industry-standard way that lowers costs for everyone. It could do for networking what OpenStack is doing for cloud computing. 

This article, “OpenDaylight: A big step toward the software-defined data center,” originally appeared at InfoWorld.com.