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Software Defined Networking: time to unshackle the network


07 April 2016

Global Services

Blogs by author: Global Services, We’re a leading global business communications provider


It’s been said that “software is eating the world.” Internet-based cloud platforms such as Amazon Web Services (AWS) and Microsoft Azure are indeed disrupting industries from the ground up. Public cloud services give startups that are unencumbered by legacy infrastructure ways to develop and deploy new applications with unprecedented speed, flexibility and efficiency. 

For many large enterprises, however, deploying new IT services in on-premise IT infrastructure is anything but fast, agile and efficient. Fortunately, that is about to change as traditional hardware-based networking is being “eaten” by software too. Indeed, Software Defined Networking (SDN) is a new architecture that gives enterprises the power to radically simplify their network, making it easier to manage, and allowing applications to be deployed in minutes, rather than days.  We asked Steve Decoster, Senior Network Designer at BT Advise, and Wouter Coppens, Business Consultant Compute at BT Advise, to explain what SDN is and what its implications are for enterprise customers.

The roots, definition and difference of SDN

Tell us about the history of SDN. Where do the underlying ideas and technologies come from?

Wouter Coppens - Business Consultant Compute at BT Advise
Wouter Coppens
Business Consultant Compute at BT Advise

SDN has its roots in a number of research initiatives that sought to separate or abstract the control and management functionality of a networking device. The Internet Engineering Task Force, for example, created the ForCES (Forwarding and Control Element Separation) protocol in 2003 which separated the forwarding and control functionalities within a network device. Two years later a team at Stanford University launched the Clean Slate project with the idea of building a networking switch from scratch. Here the goal was to build a centralized control and management system that would look at the network as a whole in making its forwarding and routing decisions (as opposed to distributed device configurations running the show).  That project led to the launch of the Open Networking Lab, a non-profit entity supported by industry that is actively promoting Software Defined Networking as the means to boost Cloud innovation.

How would you define SDN today? How does it differ from traditional network architecture?

A traditional network is typically set up using hardware-based networking devices such as switches and routers.  While new protocols have certainly made networking more efficient over the years, the basic design and implementation of such networking devices has not changed fundamentally over the past 20-25 years.  Each device typically has its own data plane (responsible for forwarding traffic), control plane (responsible for controlling traffic) and management plane (responsible for managing the device). This means that each component has to be configured individually, with all the implications thereof on network management and flexibility.

SDN virtualizes and thus decouples the control and management functionality from the device and centralizes that functionality as a purely software-based service. That simplifies the network hardware, making it more cost effective and also creating a single plane for configuring, controlling and managing the whole network.  Therefore, if you want to deploy new services you do not need to reconfigure individual components. You simply define policies that are automatically pushed to components. It basically eradicates the “stovepipe” approach in deploying IT services, whereby each deployment has to work through a series of manual, error-prone and often bureaucratic processes.

Is SDN for your business?

What kind of company will benefit from SDN?

Steve Decoster - Senior Network Designer at BT Advise
Steve Decoster
Senior Network Designer at BT Advise

SDN within the enterprise is especially relevant for large companies that have their own network and datacenter, supporting a complex and, most importantly, dynamic business operation. These companies frequently need to deploy new resources and applications, but it is a time consuming and cumbersome process, especially from a governance perspective. 

For example, BT is currently working with a large international customer that had three separate environments in its datacentre for production, development and testing. These environments were separated to reduce the risk that development and testing could infringe on the production environment.  Also, the deployment of new applications typically took weeks, undergoing several steps before these could be securely integrated in the network. Governance issues and the allocation of engineers to each of these steps created unavoidable delays.

With SDN, the entire infrastructure, including servers, storage and networking can be seen and managed as a single integrated entity. New applications and their required resources can now be rolled out in minutes.

Migrating to SDN

What is required to migrate to SDN? Where does one begin?

A migration to SDN does require new infrastructure since network components will need to be replaced with SDN-enabled technology.  During the migration you will need to run two systems concurrently.  This setup allows for smooth migration from an existing network environment to the SDN enabled Virtual Private Cloud

How can BT help? And what is BT’s longer term vision with regard to SDN?

BT Advise can support clients along the entire lifecycle, both in an advisory role and with the actual implementation. For example, we can design the SDN enabled network and architecture, but we can also validate the design through a PoC.  We also help clients integrate the software driven architecture into their installed base and can take responsibility for Project and Programme Management.

At BT Advise we have experience in SDN implementations (we took on the first SDN project in Belgium last year), we have the relationships with the vendor ecosystem, and we can rely on the global capabilities and infrastructure of BT Global Services.  Software Defined architecture is also perfectly aligned with BT’s Cloud of Clouds portfolio strategy, since it prepares the way for easy integration in the (hybrid) Cloud of Clouds ecosystem.

BT sees IWAN as one of the key stepping stones for customers when transitioning to future Network Function Virtualisation and SDN capabilities

So to sum it up, why should companies take the step toward SDN?

SDN allows you to utilize your IT infrastructure more effectively than in a classic hardware defined architecture. Moreover, you can now model your IT infrastructure to suit your changing business needs, and do so without having to change your underlying network infrastructure. That improves your business agility, and at the same time reduces your total cost of ownership.

Want to learn more? Connect with us in our BT Let’s Talk LinkedIn Group, read more here or contact us.

Related news: BT launches software-defined solutions consultancy in the Benelux

Fabrice-De-Windt-118x117“For many of our customers, deploying new services in their le/bnlxgacy IT infrastructure can be slow, rigid and inefficient. Software-defined is all about giving them the power to radically simplify their data centres and networks, making these easier to manage and allowing applications to be deployed in minutes, rather than days or weeks.”
– Fabrice De Windt, CEO BT Benelux – more