Source of an article: https://blog.cloudworldseries.com/2016/07/13/better-together-why-sdn-and-nfv-work-best-when-deployed-together/
IT organisations continually strive to deliver applications to their users more efficiently and productively to increase revenues, reduce costs and improve QoE (Quality of Experience). At the same time, IT departments are mandated to provide more agile, automated and more resilient services. The problem is that network services such as application delivery control and load balancing, web application firewalls, intrusion prevention and SSL encryption, can sometimes take days, weeks or even months to provision in data centres when new application services often need to be enabled in near real-time.
“traditional IT models are unable to provide this level of service has been one of the primary drivers for the rapid adoption of public and private cloud services”
The fact that traditional IT models are unable to provide this level of service has been one of the primary drivers for the rapid adoption of public and private cloud services. Competition has also forced IT to rethink their utility models, prompting them to consider more agile technologies, services and methodologies to provide users with the level of cloud services they need in the timelines that are acceptable and with a good QoE.
Software Defined Networking (SDN) and Network Function Virtualisation (NFV) have emerged as vehicles to provide that level of infrastructure and network services, while still maintaining visibility, security and control over the environment they manage.
While core functions differ, a very basic explanation of SDN includes the separation of network control and forwarding operations and the centralisation of control to provide instructions to the switching infrastructure. This effectively decouples the network from the underlying hardware and allows the network to better integrate with and support virtualised data centres.
“the implementation of network functions in software removes the need for physical proprietary pieces of hardware and allows the network to fully benefit from virtualised data centre technology”
NFV on the other hand, does precisely what its name implies and virtualises network functions such as ADCs (Application Delivery Controllers) and WAFs (Web Application Firewalls). The implementation of network functions in software removes the need for physical proprietary pieces of hardware and allows the network to fully benefit from virtualised data centre technology.
NFV makes ADC and WAF virtualised functions more accessible to the rest of the virtual infrastructure and provides the framework for service chaining multiple network services. By placing these virtual appliances in a hypervisor environment you create a centrally programmable infrastructure that reduces cost, by not having to maintain and support scores of physical appliances. It also improves reliability as misconfiguration and operator errors become a smaller issue.
Virtualised services at layer 4 -7 of the OSI (Open Systems Interconnection) model, which were traditionally run on purpose built appliances, are perfect for the next generation of agile networks. And with a full library of APIs, this makes them complementary to other third party tools such as orchestration and cloud management products.
To further enable agility of services within the next generation agile data centre, each major function can be delivered as a single, automatically provisioned virtual element; in NFV terms, a VNF – Virtual Network Function.
It’s one thing to provide appliances in a virtual format, but without proper tools to provision, monitor, scale and manage those virtual services and without those virtual services being a seamlessly integrated set of elements within a broader systems architecture, you are just replacing the hardware with software. This fails to truly achieve the potential of emerging technologies like SDN and NFV.
“implementing the concepts of SDN without virtualising network functions would tie the network to the world of hardware”
While it’s clearly not a conceptual requirement to implement SDN and NFV together, the capabilities of both technologies complement one another and work well together in supporting a Software Defined Data Centre (SDDC) model. As an example, implementing the concepts of SDN without virtualising network functions would tie the network to the world of hardware. This conflicts with the spirit of SDN, which focuses on putting network intelligence in software.
When you are considering a transition to a more dynamic data centre architecture that’s more closely aligned to the hosted workloads you are running – one that truly responds to the requirements set by those workloads on the network services environment – it’s critical that you:
- First consider the specific functionality you need from each of those network services solutions.
- Consider how well those functions are integrated with platforms designed to manage, monitor, orchestrate, scale and move those functions both manually and via automation.
- Make sure that the vendor providing the virtual network services provides this control capability specific to their functions.
- Ensure that the vendor also provides integration with third-party platforms that perform these functions in compute and mixed/open cloud environments such as VMware, Openstack and Microsoft.
- Finally, make sure your chosen solution has the ubiquity to run both the control functions and data plane function in public cloud environments with the same level of interoperation and integration as they can in your private data centre.
“using both SDN and NFV means that your data centre can be efficient, cost effective and reliable, while also providing greater flexibility and performance”
While the cutting edge brings technological and operational benefits, the transition can be painful. By reducing implementation risks, improving efficiency and lowering the barriers to success, using both SDN and NFV means that your data centre can be efficient, cost effective and reliable, while also providing greater flexibility and performance. The complementary nature of SDN and NFV makes them perhaps two sides of the same valuable coin and equally critical parts of a modern, efficient virtual network.