Exactly what is it?
The virtualization of networks (or Software Defined Networks – SDN) consists in offering private or business clients the possibility to manage their services and their network on demand via evolved software network functions and physical network equipment (with calculation and storage functions…) grouped together within Data Centres.
After server and storage, in turn the network becomes virtual
As is already the case for servers (computers offering services, in particular Internet access) and for storage (data storage capacity), which are accessible as on-demand and virtually instantaneous resources via the Cloud, virtualization of the network enables the user to do without physical infrastructures by virtualizing certain network functionalities in software. New network functionalities will thus be able to be deployed or updated more simply, in a more agile manner, and at less cost.
Virtualized network functions
In other words, network functions (firewall, NAT: address translation, EPC: management of mobile data traffic) are decoupled from the equipment. This is called Network Functions Virtualization or NFV.
In order to make the virtualized functions work harmoniously and coherently, notably their positions in the different Data Centres, an orchestrator is used. This network architecture model, or SDN (Software Defined Network), makes it possible to control the network, to make it higher performing, and to automate its services.
Five big advantages
1. Better accessibility: the user (the operator for example) can thus manage their network remotely via an interface.
2. More flexibility: automatic and real-time adaptation of the network in the case of peak load or hazards, without the intervention of a technician.
3. More speed: when the whole network is in software format, it only takes a matter of minutes, or even seconds, to deploy services, make changes, or restore a previous version (network reconfiguration, update of functionalities, deployment of new software solutions). These changes are automated and are even programmable.
4. Higher security: micro-segmentation enables the isolation of each work load, with independent security, thus preventing threats from spreading from server to server.
5. Less costs: a lowering of investment costs thanks to optimised infrastructure sizing (based only on needs) and operational savings (less interventions).
To use an analogy of the video game world, to go from a traditional network to network virtualization is a bit like swapping your old Atari arcade console offering only the one game (Pong) for a PlayStation 4 that enables you to download a whole range of games.