Software Defined Networking (SDN)
By: Daniel P Lundy
Tags: Computers, Networking, Software, Cloud Computing, Massachusetts

Daniel P Lundy is a sales software executive with over three decades of professional experience. Throughout his time selling software applications and database services, he has witnessed Software Defined Networking transform the information technology industry.

What is Software Defined Networking?

Software Defined Networking, or SDN, is defined broadly as being, “an approach to cloud computing that simplifies network management and makes programmatically efficient network configuration possible” The objective of software defined networking is to clearly and effectively address the reality that the static architecture of conventional networks is not only decentralized, but also highly complex whereas modern networks are more flexible and require less troubleshooting.

SDN endeavors to centralize network intelligence by separating the forwarding process of the data plane from the routing capabilities of the control plane. This control plane is typically comprised of one of more controllers and is considered to be the ‘brains’ of the entire SDN network.

How Does SDN Work?

Providers of software defined networking offer a large selection contrasting architecture sub-types, but in its most basic form, SDN centralizes network control by disassociating the control logic to off-device computer capacities and resources. Every software defined network solution has some type of SDN controller and also southbound and northbound APIs.

· What is a controller: A controller is the ‘brains’ of the entire network. Software defined networking controllers present a central view of the entire network and allows network admins to communicate to the underling systems (such as routers and switches) how network traffic should be handled by the forwarding plane.

· What is a southbound API: SDN uses southbound APIs to deliver vital information to the switches and routers below the network. To date, OpenFlow (the first SDN standard) remains the most commonly utilized protocol.

· What is a northbound API: SDN uses northbound APIs to relay information to applications and business logic above the network. These API’s make it easier for administrators to deploy services and programmatically shape traffic.

The Benefits of SDN

Software defined networking boasts a centralized and programmable network that can be dynamically provisioned in order to address a number of evolving business needs. SDN also delivers a number of benefits, including:

· Central management capability: network intelligence is centralized in software defined networking controller software, and maintains a complete view of the entire network, which is present to applications and SDN network policy infrastructure as a single, logical switch.

· Reduced CapEx: SDN has the potential to limit the requirement to obtain purpose-built, ASIC-based networking infrastructure and, as an alternative, supports a pay-as-you-grow environment.

· Reduced OpEx: Software defined networking facilitates algorithm control of various network elements (like hardware or software routers and switches) that are becoming increasingly more programmable. This means that it is easier to design, deploy, manage and grow these types of networks. As well, the capability for automated provisioning lessens the risks of human error and also reduces the need for physical management of the network.

Having said that, there are drawbacks to intelligence centralization when it comes to things like scalability, elasticity and security, making this the primary issue of software defined networking. However, in the majority of instances, the benefits of Software Define Networking significantly outweigh the negatives.