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Virtualization is usually discussed in the context of virtual machines as a way of dividing up the enormous power of contemporary microprocessors among simultaneous but unrelated operating environments. But virtualization can be applied more loosely to mean substituting services, even those provisioned in the cloud, for capabilities historically deployed on local servers or other physical network infrastructure.
So, the question arises: Just how much physical network infrastructure could be virtualized in this manner both for enterprises and network operators?
The answer in both cases is: almost everything. In fact, the term network functions virtualization describes exactly what we have in mind here. Obviously, a few issues need to be considered before virtual network infrastructure becomes common, but the implications are dramatic regardless.
A network in the cloud? Network as a service? Yes to both. I'm betting this is the path forward for almost every network everywhere, with software-defined networking providing the incentive to innovate and bring about many of the resulting benefits.
This brings us to a question I've been asking clients and others lately: What does the network of 2020 look like? Or for the more adventurous, what will the network of 2025 look like?
To get an idea, let's look at the key trends that are gaining traction:
- Wi-Fi as primary or default access for the enterprise network;
- Ethernet switches functioning primarily as interconnect and power for Wi-Fi access points (APs);
- Routers serving more as Layer 3 switches connecting to Ethernet and IP-based wide area networks;
- The rise of high-performance cloud-based services (with their implied reliability, resilience, cost-effectiveness and scalability); and
- Greater and more cost-effective processing power available across the board.
Looking at these influences, it's easy to see precisely how physical network infrastructure will evolve and consolidate over the next 10 years. For example:
- Wi-Fi access points will remain the primary and default access for almost every client device, from handsets and tablets to the Internet of Things. Every available bit of radio spectrum at 900 MHz and 2.4, 5 and 60 GHz will be used, with the resulting capacity sufficient for almost every application. We'll even see 10 GbE over the air.
- Consequently, Ethernet switches will quickly, cost-effectively and, perhaps surprisingly for some, evolve to 10 GbE as the default, with 1 GbE no longer adequate, and interest in 2.5 and 5 GbE rapidly diminishing.
- Router functionality will be built in as an option in those very same Ethernet switches, much as we see in residential-class routers today. And, yes, resilience and fault-tolerance across the board will become standard and relatively simple.
Here's the surprising part: That's it. That's all the "real" infrastructure required.
What happens to the rest of the physical network infrastructure?
Everything else -- network management, performance optimization, analytics, security and the SDN controller itself -- will be virtualized and provisioned in the cloud. That cloud might be public or private, but public cloud will increasingly be the path of choice given the cost-effectiveness, reliability and on-demand scalability inherent in the public cloud model. Given very-high-performance links to the Internet (10 Gbps or more will be common), there's no performance penalty compared to local implementations. The savings on local equipment and physical network infrastructure might easily pay for a strategy that is preferable regardless.
As continues to be the case, SDN is both the catalyst and the driver for this vision becoming reality. The essence of SDN is in the fundamental programmability of network infrastructure, and the less diversity in this infrastructure the better.
Scalability means adding more of the same elements. Again, these elements are just APs and switches -- APs and switches based on SDN, that is. The inherent performance of advanced processors and interfaces coupled with the flexibility and extensibility inherent in SDN then appear to be key guideposts on the path to networking nirvana.
Our work to date here is hardly exhaustive. And change, even in technology, occurs more slowly than most of us would prefer. But there's little denying that moving toward SDN is perhaps the most important direction overall in networking today. Coupled with the evolution of hardware capabilities discussed above, it's easy to see how the expanding role of SDN is bringing along a broad range of additional benefits.
Network hardware's role in virtualization and overlays
Network infrastructure will evolve, not face its demise
Managing physical and virtual networks in parallel