Software Defined Networking - "The Biggest Thing Since Ethernet"

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SDN Authors: Liz McMillan, Elizabeth White, Sven Olav Lund, Pat Romanski, Destiny Bertucci

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The Road to SDN Is Paved with Visibility By @JKonstantas | @CloudExpo #SDN #Cloud

SDN stands to transform our modern networks and data centers, turning them into highly agile frameworks

Network architectures are in the midst of a massive transformation. Not too long ago, traditional network designs began to strain under increased demand for compute and storage. This saw the advent of server and storage virtualization, giving organizations on-demand access to the resources required for supporting service-oriented architectures and machine-to-machine communications. The increased agility and provisioning of virtualization showed the immense flexibility of decoupling key network components from the underlying hardware and catalyzed what is now a movement toward software defined networking or SDN.

Before SDN, network infrastructure had not seen massive change in decades, partly because today's high performance networks run on purpose-built hardware with custom silicon that represents an enormous investment on the part of the companies that have brought them to market. Enterprises have also devoted significant resources in employees with specialized skills and certifications that are required to maintain today's network infrastructure. This state of affairs has made any kind of customization or network-design flexibility nearly impossible until recently.

With SDN, enterprises have more choice in the infrastructure they use. Off-the-shelf hardware, with or without the OS and basic networking services installed, are available, as are "white box" switches marketed for precisely their flexibility and customization. Network designers still have to make some trade-offs in performance versus flexibility, but with more latitude than ever before. In fact, many vendors of purpose-built "appliances" for network and networking services now offer their functionality as software-only bundles and subscription services.

The Role of Visibility in SDN
SDN stands to transform our modern networks and data centers, turning them into highly agile frameworks that can be quickly reconfigured for changing business needs. Still, a lot of organizations recognize that highly mobile workloads and auto-configured applications and services by their nature result in weakened security, less visibility over traffic on the network when using traditional tools and the loss of performance optimization capabilities.

Network visibility is a foundational element in terrestrial networks and becomes more critical in highly dynamic SDN architectures. Loss of network visibility does not need to hinder firms from moving forward with SDN, however. There are companies that have taken steps to engage both the standards community and the leading vendors of SDN architecture to ensure that application performance and security are maintained during an SDN migration and after its completion.

What is necessary to maintain network visibility in an SDN environment is a centralized, highly scalable Visibility Fabric that delivers intelligent traffic and serves as a pervasive layer throughout the deployment. Pervasive visibility of all traffic flows and packets on the network is vital for monitoring the state of the SDN network, monitoring the applications it enables, and ensuring that security is maintained across the network. Without these three requirements, SDN deployments can't succeed.

Whether the SDN architecture of choice is built on OpenFlow or network virtualization abstractions such VMWare's NSX and Cisco's ACI, or still some other framework, the key requirements above remain. In SDN, control and forwarding layers are managed independently, yet need to function together. Synchronization issues between these layers due to network latency or vendor variance in networking infrastructure can cause bottlenecks and disrupt operations.

When it comes to SDN applications and services, the benefits of on-demand provisioning are undeniable. But, this sort of dynamic configuration can result in unpredictable traffic patterns that become hard to troubleshoot via traditional means, which place performance management tools at predictable places in the network. Visibility into such traffic in the SDN realm needs to be constant and the tools centralized so that they can receive all traffic flows and packets.

Similar logic applies to the need for security. Whereas security devices could be placed on critical network segments in traditional networks, this is untenable in SDNs. Centralized placement and total access to all inter-SDN traffic gives security technologies the best statistical chance of surfacing embedded malware and anomalous patterns.

SDN, NFV and network virtualization are finally a reality, transforming networking permanently and for the better. Most organizations will make the transition embracing one, two or all three concepts. Those that will make the journey with the least amount of disruption will be the ones that understand that traffic visibility is fundamental. On-demand networking brings unprecedented agility, scale and dynamism to network design. Understanding traffic pathways and baselines before, during and after the SDN migration means knowing how well the transition is delivering on CapEX and OpEx promises, as well as the potential for higher security. It is impossible to understand what can't be seen, which is why the road to SDN needs to be paved with visibility.

More Stories By Johnnie Konstantas

Johnnie Konstantas heads Gigamon’s security solutions marketing and business development. With 20+ years in telecommunications, as well as data and cybersecurity, she has done a little bit of everything spanning engineering, product management and marketing for large firms and fledglings.

Most recently, she was the VP of Marketing at Dato, a company pioneering large-scale machine learning. She was also VP Marketing at Altor Networks (acquired by Juniper), an early leader in virtualization security and at Varonis Systems. Past roles have included product management and marketing for Check Point, Neoteris, NetScreen and RedSeal Systems.

Johnnie started her career at Motorola, designing and implementing large-scale cellular infrastructure. She holds a BS in Electrical Engineering from the University of Maryland.

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