So, for the CEO who wants the maximum amount of flexibility and agility from invested resources, SDN certainly holds a lot of promise. Think of SDN as the controller who sits within an elevated plane of existence above the underlying network hardware. Instead of distributed and fragmented controls at the level of individual devices, SDN gives administrators a consolidated, centralised and high level control layer of the entire network.
What does this mean for the business? At the simplest level, a business application might require a change in data flow requirements, which is not supported by the network's current configuration. An SDN controller with sufficient intelligence built into it would be able to recognise this discrepancy and automatically re-configure all the relevant devices in the network to support that data flow, instead of merely alerting the operator for manual intervention - at each device.
Another example of the benefit of SDN lies in authentication and access control. If a business deploys a virtual desktop infrastructure (VDI), one of the key challenges would be to maintain consistent policies between, say, an office in London and a data centre in Berlin, especially when the virtual desktop is being accessed via a range of devices - from smartphones and tablets to desktop computers. Here, a central SDN controller can keep track of users and devices at both ends of the network, and ensure that consistent authentication, admission control, and authorisation policies are maintained.
While SDN has the potential to revolutionise the way networks are designed, the natural progression is for organisations to look at a non-proprietary, open standards-based approach. For SDN to take off, a universal language between the complex devices - to communicate with each other - is a fundamental requirement.
OpenFlow - which has now become the most popular protocol for SDN - is designed to provide the communication standard for network devices to talk to one another, without requiring network vendors to expose the internal workings of their devices. OpenFlow allows easy deployment of innovative routing and switching protocols in the network, offering a programming interface that enables high degrees of automation for business critical applications. Already, Google's successful experience designing its WAN networks based on OpenFlow principles is an affirmation for organisations looking to scale their data centre infrastructure.
SDN holds plenty of promise
OpenFlow is here and today many network switch and router vendors are joining the bandwagon to showcase their compliance with OpenFlow. The move towards a software-centric network has already started at the edge of the network, as a result of the demands placed by cloud computing and mobility. Ultimately, SDN will transform networking in the data centre in the same way virtualisation has transformed compute and storage resources.
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