How software defined networks enable optimised application delivery

A completely disruptive technology has been introduced to data centre computing over the last decade. Virtualisation has provided enormous flexibility, including the ability to dynamically optimise resource utilisation based on workloads. As a result, application architectures have evolved. Applications can now be decomposed into components that run in their own virtual machine containers while sharing the same physical server.

Virtual machines delivering a single application can be spread across multiple servers in the data centre or even between data centres, and moved rapidly between servers to optimise delivery performance. In effect, virtualisation has enabled significant automation and cost reduction in the data centre.

Unfortunately, this new found flexibility at the data centre computing level has not been matched by an equivalent capability within the physical network. Today’s data centre network has very little awareness of the applications that are generating traffic and, conversely, the new virtual application control systems are unaware of the conditions prevailing within the network. Thus the network and the applications are operating in silos and any attempt by the network or the application controllers — the hypervisor — to improve network resource utilisation usually leads to sub-optimal results.

What value can SDN bring?
The SDN approach must go beyond simply automated configuration of network elements to focus on the entire user experience.

Today’s data centre network has very little awareness of the applications that are generating traffic and, conversely, the new virtual application control systems are unaware of the conditions prevailing within the network. Thus, as we have said, the network and the applications are operating in silos.

SDN provides an approach to networking in which a coordinated approach to network control enables a centralised view on network conditions, which can consequently be used to augment policy-based control elements in each network device and provide visibility on network conditions to application control platforms such as hypervisors.

In this way, SDN bridges the gap between the network world and the newly virtualised compute world by defining a framework that uses standardised interfaces between applications and networks. Currently, industry attention is focused on southbound Application Programming Interfaces (APIs) that detail how an SDN framework interacts with the network.

A number of communication protocols and interfaces, including existing protocols such as NetConf and Simple Network Management Protocol (SNMP), as well as new approaches based on web services, such as Representational State Transfer (RESTful) and Simple Object Access Protocol (SOAP) APIs are being discussed and can be used to realise this. OpenFlow is another such protocol.

Focus on the all-important user experience
This infrastructure will allow applications and the network to collaborate to provide a high quality experience for users and enable optimisation of resources.
The ideal solution to delivering automation to an enterprise network using an SDN approach is to provide three key objectives:

Programmability, which will provide a link between the application control and network control layer. This will optimise application delivery performance and increase visibility.
Application fluency, which will allow the network to automatically identify and provision applications and react to any subsequent movement of virtual machines. This will unleash workload optimisation capabilities now available and enable the network to dynamically adjust to application traffic flows, thereby providing a high quality user experience.

Global control view, which will be maintained by the network to provide application and network control systems with a global view of network conditions. This can help improve decisions on how to treat traffic streams of a particular application, as well as improve decisions made by application control systems concerning placement of virtual machines.

The future – where will this journey take us?
SDN is certainly still in its infancy, and for it to work effectively, vendors need to embrace a collaborative, open, service-first based approach to their customers. The benefits for businesses will be huge:
£ Better and more consistent user experience
£ Improved network efficiency – centralised management, better
service control across whole network fabric for any device, user or
application. Decreased complexity.
£ Huge operational cost savings
£ Improved IT agility
£ Supports multi-vendor environments
£ Advanced analytics – of the network and its performance

One of our customers already witnessing the benefits of SDN is CandIT Media, a digital media solutions company based in Belgium. It is our first customer to validate the application fluent approach to enterprise scale SDN in order to provide proprietary digital media production solutions that meet massive data storage and real-time file transfer requirements. The company has created a “content aware” digital network that dynamically supports the large traffic peaks specific to media flows. In addition to providing a higher quality user experience, CandIT Media can deliver solutions to its customers at lower costs since the network is more efficient in transporting large files.

The goal of SDN is to bring automation to the data centre. If done properly, it will provide an evolutionary path to deliver coordinated activity between the network and application control platforms covering new and existing networks. Application Fluent Network technology makes this possible by providing a rich policy infrastructure that can work autonomously or in a coordinated fashion to adjust and optimise an entire corporate IT infrastructure ensuring it can seamlessly support real-time applications – and this will be essential to businesses of any size in order to deliver mission-critical applications securely to employees, no matter where they are.