Subscribe / Unsubscribe Enewsletters | Login | Register

Pencil Banner

Addressing WAN edge networking complexity with SDN and NFV

Dave Corley | April 8, 2014
As enterprises add mobile users, virtualized services, and public and private clouds, they're running into constraints that threaten to limit their ability to scale their network infrastructure appropriately. Contrary to what many assume, the constraints are not so much bandwidth and cost, the real culprit is complexity.


The good news is that over the next several years large portions of the static, distributed legacy network will likely be replaced by Software Defined Networking (SDN), an evolving network architecture that decouples network control from thousands of specialized, distributed network switches and routers and moves it into centralized software. If SDN plays out the way it's intended, future networks will be configured centrally via intuitive graphical software rather than switch-by-switch and router-by-router using the arcane command line interface (CLI).

Centralized control will make configuring new services and their network requirements and adjusting to network congestion and other challenges a much easier and faster process throughout the network. Centralized management also promises to help IT achieve better visibility into the entire network than it has had until now, so IT will be able to monitor and adjust networks more successfully as they scale and change to accommodate new circumstances and services. The CLI will still be available, but used only when engineers need a highly granular diagnostics interface to dig deep into the bowels of complex networking systems in order to address more challenging network issues.

Automation will be the second benefit of decoupling network control from lower level network nodes, thanks to SDN's northbound and southbound interfaces. Southbound interfaces allow SDN network control software to communicate with lower level network nodes, including network and virtual switches and routers. OpenFlow is a standardized southbound interface under development whose purpose is to allow control planes to communicate with networks of multivendor hardware to discover topology, define network flows and implement requests coming in from the northbound interface.

The northbound interface is the interface between applications and the control plane. Its beauty is that it allows applications to tap into the control plane to make requests for bandwidth, quality of service, and other functions automatically. Not only will management applications harness the northbound interface for centralized network visibility and IT control, but applications such as VoIP will be able to draw the bandwidth, quality of service and other network services they need to fulfill their performance and latency requirements automatically. Ultimately, applications may provide network self-healing and adaption capabilities that automate network fault detection, isolation and remediation workflows under centralized policy control.


NFV works hand-in-hand with SDN, turning what was once dedicated network hardware into virtual machines that can sit on any server along with other applications and services. There was a time when server-based switches and routers couldn't compete in performance and functionality with their specialized, dedicated, physical counterparts, but with advancements in the technology and more powerful servers used in the virtual environment, they're catching up fast. NFV is becoming perfectly usable in all but the most demanding network environments.


Previous Page  1  2  3  Next Page 

Sign up for CIO Asia eNewsletters.