Network virtualisation has many benefits. It explains why network operators and vendors have invested so much in advancing this category of technology.
The primary benefit is the flexibility that virtualised networks allow. Unlike physical networks, it’s relatively fast and easy to change the configuration, topology, function and usage of virtual networks. Physical network changes tend to require human intervention, often with long planning cycles. By contrast, virtual networks can be changed almost instantaneously, not to mention being modifiable using algorithmic / automated techniques. This allows the networks to be optimised for usage patterns and performance targets in near real time.
The second benefit is segmentation, allowing separation of traffic by types, users, security requirements and more, all the while utilising the same, un-differentiated physical plumbing. Software architectures like SD-WAN can give the impression of dedicated (unshared) network resources, even though underlying physical infrastructure will invariably be shared.
The third benefit is resiliency, where traffic paths / routes can be adapted as needed, whether that’s to enable routing around a failure, handling more/less capacity, or enabling a new path if initial connections are degraded / interrupted.
Without modern OSS tools, virtualised network benefits are just a dream
The downside of network virtualisation is that there are extra complexities that need to be managed. The extra complexity makes troubleshooting more challenging. And despite the security benefits of segmentation, the centralised control aspect and increased complexity of virtual networks introduces exposure to cyber attack.
But before diving deeper into how virtualised networks impact OSS, we’ll introduce an analogy that helps to understand how network virtualisation works. Think of physical networks like transport lanes – highways, side-streets, shipping lanes, flight-paths, sidewalks, rail-links and more. There are many ways to get from point A to point B. However, like optical fibre cables and physical network devices, these transport lanes all require planning and can be time-consuming to build / commission.
Intersections, traffic lights and interchanges are the traditional traffic routing mechanisms in play using this analogy. Together with the transport lanes, these interconnects make up “the data plane” equivalent in virtual networks.
Virtualised networks are more dynamic. Can your current OSS solutions keep up?
Virtual networking introduces a new concept within this analogy though. It has a completely dynamic, adaptive way of moving a payload between points A and B. It uses onboard signalling (e.g. head-up displays within vehicles), variable signage and traffic controls to optimise movement of traffic. It could assign a dedicated lane to a VIP like a QoS policy. It could show pre-determined source/destination for an organisation (e.g. head-office and depot like an SD-WAN), but direct vehicles along different paths depending on congestion points at any given time. It could shut down certain lanes on highways to reduce wear under light loads like bandwidth on demand (BoD). All of this signalling is controlled in near-real-time using centralised, coordinated software. This is equivalent to “the control plane” in virtual networking. Closely related is “the management / policy plane,” which collects current performance and flows, to influence the configuration of the control plane.
The control and management planes can help to set up networks with the flexibility, segmentation and resilience discussed above. Being defined in software means that all of these behaviours can all be adjusted on-demand.
When associating this analogy with the OSS that manage physical and virtual networks, it’s clear that the connections between planes are important to coordinate. The data plane, the fibre cables and physical equipment, doesn’t change much from day to day. However, the overlay networks or control plane can change from minute to minute. Active network inventory solutions need to establish and maintain the relationships between data, control and management planes to retain control of the network and all its layers.
What does it take to realise the potential benefits of Network Virtualisation?
Network Inventory solutions that have static, structured data models struggle to cope with virtualised network modelling without customisation. Due to its highly adaptable data modelling framework, SunVizion Network Inventory is able to model network resources of physical, logical and virtual types in a flexible and hierarchical manner. This is further supported by SunVizion Network Configuration Management for tracking and managing the current state of the network, both physical and virtual / overlay networks.
Virtualised networks offer powerful benefits to network operators. However, they also need modern active inventory, network configuration and network orchestration solutions to fully realise the benefits.
