The Future of Software-Defined Networking
Software Defined Network (SDN) has been discussed for years. In this series, Craig Mathias looks at what impact it will have on Wi-Fi and why it’s needed.
Last week, we looked at the new opportunities that SDNs and Wireless-LANS have when working together. We began this series with the observation that networking should be, at this point, more static and mature than it actually is. After all, networks are conceptually simple in operation, networking is ubiquitous in organizations, residences, the wide area, and everywhere else today, and lower costs and (consequentially) much-improved price/performance have allowed straightforward (and brute-force) optimization techniques like overprovisioning to suffice.
SDN is an innovation that will dramatically change this traditional thinking over the next few years, adding intelligence, adaptability, and much more. While not yet close to pervasive, vendors are introducing new SDN products at a rapid rate. The next refresh cycle is right around the corner – SDN will indeed be everywhere.
SDN in fact points to a future that is much more driven by availability and transparency than has historically been the case in networking. The interruptions to service (and, often, the associated extended periods of unreliability) that have traditionally accompanied network upgrades are no longer any more necessary than they are acceptable.
And routine changes to policies – even, in some cases, automatically put in place as anticipated conditions arise – are now beginning to substitute for what was once viewed as unavoidable congestion, outages, and forced upgrades with numerous associated risks.
So, then, the future of SDN is nothing short of bright. In fact, we expect SDN to become broadly pervasive over the next five years, as standards progress, the benefits become quantified, and end-user organizations proceed down the experience curve.
One of the very interesting possibilities now appearing is the merging of SDN with that other leading-edge trend in networking, network function virtualization (NFV). NFV, like all virtualization technologies, substitutes software-based constructs for what would otherwise require dedicated hardware.
A virtual machine, for example, is really just a software implementation of a real processor, using specialized hardware to speed certain elements. Moving network functionality into virtual machines and even the Cloud, which may become the most popular form of NFV, is already at work in carrier networks, substituting code running on otherwise general-purpose processors for dedicated hardware implementations of functionality defined in standards.
Virtualization in this case, sometimes called networking as a service (NaaS), enables a greater degree of reliability and fault-tolerance, scalability – even on demand, as customer-driven traffic volumes grow – and the ability to grow solutions organically without disruption.
Sounds a lot like the benefits of SDN, doesn’t it?
Open source will also play a role in the eventual dominance of SDN. The OpenStack infrastructure-as-a-service (IaaS) offering has already achieved a degree of popularity, and includes a good degree of networking functionality. The OpenDaylight Project is specifically designed to implement an open-source platform for both SDN and NFV. Other open-source implementations are well underway, but we must admit that some proprietary solutions will also see success.
SDN may also help us address one of the truly insoluble problems in networking and IT overall – security. Because SDN implements policy, a high degree of traffic-flow monitoring and management is essential. SDN implementations can thus be programmed to look for anomalies that might represent a denial-of-service attack, an attempted break-in, or unusual activity that might indicate data being compromised.
Networking has evolved over the past three decades driven by extremely high (and increasingly mission-critical) demand, rapidly evolving hardware, software and protocol technologies, and a hyper-competitive marketplace.
The result, perhaps inevitably, has been complexity, albeit with a high degree of interoperability in basic services. SDN promises to re-shape networking into a more unified, “softer” facility that simplifies network services and operations, improves scalability, and simplifies operations (essential as demand in terms of number of users and devices as well as traffic volume and time-boundedness continues to grow), improves interoperability, and all within the framework of a contemporary, policy-driven strategy.
And, yes, wireless LANs will be very much at home in the world of SDN.
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