Network functions virtualisation (NFV) is set to revolutionise the communications industry with its unique ability to shift the running of networks from traditional hardware to open-based computer servers that can be deployed wherever required. Once NFV is in place, software defined networking (SDN) is used to provide an architectural approach that separates the control and data planes of a network. SDN provides greater control of a network through its programmability and allows applications to work in tandem with the network. As per estimates, 90 per cent of global operators are currently evaluating the deployment of SDN. Also, the annual spending on SDN-related equipment has been estimated to reach $29.5 billion per year by 2018. Therefore, there is an increased requirement for testing solutions that can validate these technologies and accelerate their adoption by service providers, data centres and enterprise networks.

Testing in NFV

A combination of both virtual and physical products can be used for NFV testing. A physical testing solution can be deployed to evaluate high-scale traffic and measure stress on the network. Meanwhile, a virtual testing solution can be deployed to measure voice or video quality or transaction latency. These solutions help improve the performance of virtual applications, accelerate the time-to-market and reduce the capex and opex associated with traditional testing equipment.

Currently, NFV providers can easily set up and run tests to deploy virtual appliances and applications. These virtual test functions are valid in three service-related areas – configuration, quality of experience, and assurance. Under these virtualised test functions, users have to set up a virtualised test fabric that emulates their desired deployment architecture including the choice of hypervisors, guest operating systems, reference server set-up, NFV, as well as other technologies such as SDN controllers and switches. By virtualising testing appliances, end-users can run this technology on hypervisor hosts where the virtual functions reside. This will allow performance testing of virtual switches and hypervisors.

Virtual test assets can play an important role even in hardware testing by reducing the number of technicians required to conduct tests. According to experts, such NFV testing solutions can benefit operators that are considering deploying NFV. At present, the industry is spending cautiously on NFV, primarily because of the pending decisions regarding what level of network virtualisation needs to take place. Operators know about the performance of their physical equipment. Therefore, they have to make sure that by using virtualised software and off-the-shelf equipment, the quality of service for their end-users is not impacted.

Testing in SDN

SDN testing is imperative to meet the demands for accessibility, connectivity, server processing, as well as new applications and services. Currently, equipment manufacturers, service providers and enterprises conduct SDN testing through OpenFlow. In the recent past, most of the testing was focused on the OpenFlow Switch including software-based switches, hybrid-based switches and purpose-built switches. However, the testing of OpenFlow-enabled devices is now more focused on the conformance of standards and benchmarking. In spite of this, what has been lacking is the testing of SDN controllers. Service providers looking to deploy SDN are now focused on ensuring that the controller provides performance, scale and features that are required for their network environment.

Meanwhile, the dynamic nature of networks within an SDN environment also poses a challenge because it may be difficult for network managers to predict the infrastructure demands. According to industry experts, separating the control plane from the data plane through SDN may require testing the performance of the two planes independently. Further, measurements of latency and throughput will be particularly important in the coming years.

SDN vendors have now introduced comprehensive solutions that cover the various requirements for conformance to standards and functional and performance testing. The increasing number of SDN solutions built on OpenFlow specifications offer easier deployment in terms of compatibility with various networking environments. Under these specifications, millions of flow variables, and traffic and behaviour patterns are defined, which allows operators to assess network quality of service and end-user quality of experience.

Conclusion