The complementary nature of SDN and NFV makes them equally critical parts of an efficient virtual network.
IT organizations strive to deliver applications to their users more efficiently and productively in order to increase revenues, reduce costs, and improve quality of experience. At the same time, IT departments are mandated to provide more agile, automated and resilient services. Network services cannot take days, weeks or months to provision, which is often the case in current data centers. In many cases, new application services need to be enabled in near real-time.
However, traditional IT models are unable to provide this level of service, often driving the rapid adoption of public cloud services and, to a lesser extent, private cloud services. That competition has forced IT to rethink its utility models and prompted it to consider more agile products, services and methodologies.
Software-defined networking (SDN) and network functions virtualization (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, as well as centralization 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 virtualized data centers.
NFV, on the other hand, does precisely what its name implies and virtualizes network functions such as application delivery controllers (ADCs) and 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 virtualized data center technology.
NFV makes virtualized 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 costs less to maintain and support. It also improves reliability because misconfiguration and operator errors become smaller issues.
To further enable agility of services within the next-generation agile data center, each major function traditionally found within a single appliance can be delivered as a single, automatically provisioned virtual element; in NFV terms, a virtual network function.
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 center 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 center 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.
- Next, consider how well those functions are integrated with platforms designed to manage, monitor, orchestrate, scale and move those functions both manually and via automation.
- Ensure that the vendor providing the virtual network services provides this control capability specific to their functions.
- Ensure the vendor provides integration with third-party platforms that also perform these functions in compute and mixed/open cloud environments.
- Ensure 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 within your private data center.
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 center can be efficient, cost effective and reliable, while also providing greater flexibility and performance.