Even in a single metropolitan area, service providers deploy dozens of routers and appliances with custom ASICs, running millions of lines of code and performing specialized functions. The costs involved in increasing capacity raises the cost per gigabyte, and is increased still further by operational expenditure for on-going management of services, power consumption, and the cost of employing the increasingly rare but necessary skills. Given the complexity of today’s networks, the provision of a new service, even a simple one, to meet customer demand can take months.
The success of virtualization methodologies that have provided flexibility in IT environments is encouraging network operators to adopt similar techniques. Network Functions Virtualization (NFV) has become a hot topic as a potential solution.
The benefits of NFV
NFV adapts IT virtualization technology to provision many of the functions provided by traditional network equipment on industry-standard high-volume servers, switches and storage located in data centres, network nodes or in end-user premises. Instead of deploying separate boxes dedicated to specific network functions such as edge routing, BNG, DPI, IPSec gateways, mobility gateways, and security functions, the same functions are run as virtual machines in ordinary high power servers.
This offers immediate benefits. Fewer boxes means lower capital expenditure and less power consumption, while software flexibility allows faster roll-out of new services with less risk. Other benefits include:
- Multi-version and multi-tenancy network appliances sharing resources;
- Services targeted on geography or customer sets;
- Greater openness for pure software firms, small players and academia to join the ecosystem.
Potential use cases include:
- Virtualized content distribution networks would allow on-demand service scaling;
- Network nodes can now support BNG, PE routing, and CG-NAT on standard high-volume servers;
- Residential gateways and set-top boxes can be virtualized;
- Virtualizing the mobile packet core functionality allows more flexibility to manage increasing traffic and dynamic loads;
- Virtualized security capabilities – firewalls, IDS, IPS and WAN acceleration deployed in a server on the customer premises – means fewer dedicated appliances and fewer visits to site;
- Software-based DPI implementations can provide traffic analysis and reporting of service security and quality.