The next generation of networking is more complex and multi-functional compared to the networks of today. Networks are moving from “connectivity as a service” to “multi- service platform.

Takeaways

SDN & NFV are complementary technologies NFV depends on SDN to deliver network features that enable it. Both use controller concepts for Operations and Administration (OAM). NFV offers two general types of services, network and user.

Comparing SDN & NFV

Software Defined Networking operates the forwarding layer in a network. There are many sub-technologies here such as overlay/encapsulated networking, controllers, APIs and applications that replace the previous generation of forwarding technologies. Networking could be performed directly in hardware using technology like EVPN/MPLS or using overlay like VXLAN/MPLSoGRE depending on market development over the next few years.

Network Functions Virtualization is focussed on network appliances that perform path control, protocol manipulation, logging/monitor/capture, content analysis, security control and similar functions. These functions are in use today as routers, firewalls, IDS/IPS, proxy caching, WAN acceleration, data centre and WAN load balancers. But also include services such as identity & authentication management (IAM) with AAA, data loss prevention, malware/virus inspection/detection, content.

Virtual Appliance

Today, NFV services are most likely to be deployed using virtual appliances operating on a x86 hypervisor.

Functional Elements of SDN & NFV

If you read the previous section and found it confusing, you are not the only one. I am attempting to summarise complex concepts. The following diagram should provide more comprehensive view of how network functions break down.

There are four general areas I consider make up a complete NFV platform.

A flow managed network can be programmed predictable and safely so that packet, flows and paths are able to integrate with mobile virtual appliances. SDN Applications and controller that can manage, monitor and analyse the overall network status and integrate with the NFV controller system. Network Services are basic network functions such as firewalls, traffic shapers. The key factor is that they operate on protocol flows between endpoints in the network. User Services that support network services, or provide additional network function. For example, AAA/IAM functions may support VPN devices for user management while security monitoring (ie capture/inspection) is a user service.

The next piece of NFV is how to provide services to a network conversation and is called “Service Chaining”.