Apr 17 2014

Why Software-Defined Networks Need Open Standards

OpenFlow interface promotes interoperability and eliminates vendor lock-in.

Public-sector IT leaders face many challenges, including tight budgets, limited staff and the need to meet employee and constituent requirements in an era of bring-your-own-device and cloud technologies. Software-defined networking (SDN) architecture can help reduce IT costs and simplify service delivery by virtualizing network infrastructure and centralizing control.

Solid Solution

SDN separates the control and forwarding planes, centralizes network control in a software controller and abstracts applications from the underlying infrastructure. The technology yields unprecedented network programmability, automation and control.

The benefits range from eliminating vendor lock-in and automating network configuration to supporting unified management of wired and wireless infrastructure and seamless hand-off between private and public clouds. However, these benefits can’t be realized without industry adoption of standard interfaces in the right places. That’s why the Open Networking Foundation (ONF), a user-driven organization with more than 120 member companies, is dedicated to the promotion and adoption of open standards.

Some manufacturers implement SDN in proprietary ways or reuse standards designed for other purposes. ONF believes that vendor-neutral, SDN-specific standards are the key to driving innovation and maximizing SDN’s benefits. To that end, ONF defined OpenFlow, a southbound interface between control software and the underlying network hardware.

Open Up Your Networks

Implemented on network devices and the SDN control software, OpenFlow enables rapid innovation in the forwarding and control planes. For example, with direct access to and manipulation of the forwarding plane, SDN software can control any OpenFlow-enabled network device from any manufacturer, including physical and virtual switches and routers.

Consequently, IT can buy best-of-breed network devices, promoting competition and eliminating vendor lock-in. Likewise, IT can use a single set of OpenFlow-based orchestration and management tools to deploy, configure and update devices across the entire network, as well as define policies centrally and have them applied consistently across the entire infrastructure.

OpenFlow also enables innovative tools that automate management tasks to reduce operations complexity, save time and money, and empower the network to respond dynamically to changing conditions, with little or no operator assistance.

What’s Next for SDNs

Now that OpenFlow has been implemented in network hardware, the Open Networking Foundation is addressing the need for northbound interfaces (NBIs) that enable a software-defined network to convey its capabilities to applications, and for applications to convey their requirements to the network.

There’s considerable variation in northbound interfaces because there are so many types of applications. Network service providers, orchestration systems and application developers, for example, must write to different interfaces to serve diverse use cases. To address the need for open NBIs, ONF established the NBI Working Group last fall.

The group is working to identify which NBIs serve which needs and to define information models that convey network capabilities and application requirements. By prototyping and gaining feedback on examples with real code, ONF will validate these NBIs. The goal is to have working implementations by the end of 2014 to stimulate further innovation.

Without open standards, no technology can realize its potential. Through ONF’s work, SDN is already delivering on its promise. For example, state and local governments have found that cloud technologies are the best way to save money and deliver modern services. Open SDN standards enable cloud providers to support multiple customers with economies of scale and elasticity, which is very good news for the public sector.

Wavebreakmedia Ltd/ThinkStock

More On


Become an Insider

Unlock white papers, personalized recommendations and other premium content for an in-depth look at evolving IT