By 7 November 2017 | Categories: Misc



Computer networks are the heart of modern communication, and Software-Defined Networking (SDN) is considered a revolution in terms of how today’s networks are designed, built and operated. 

“SDNs are far more agile than the LANs and WANs of the past. Their elasticity allows them to quickly adapt to changing businesses needs. And, in a world where it’s all about ‘connect, collaborate and communicate’, SDNs offer the added advantage in that they lower both operational and capital costs due to the use of network abstraction, virtualisation and orchestration. This makes them not only valuable, but also highly accessible in the market,” says Anton Jacobsz, managing director of African value-added distributor, Networks Unlimited. 

According to the Global Scalable Software Defined Networking Market – By Use Cases, Industry, Geography, Trends, Forecast 2017 – 2022 report, by 2019-2020, 40 to 45 percent of network spending will be on SDN. 

As a distributor that found its roots in providing best of breed networking to South Africans, Networks Unlimited has grown its footprint both geographically and product-wise, offering the greater African region verified and innovative solutions to boost its customers’ path to digitalisation. 

“Whether it is fighting a barrage of botnets flooding your bandwidth, connecting users and enhancing your applications over various locations and distances, enabling a new agility and preparing organisations for a data-rich future, dreaming big on the cloud, or implementing cost-effective yet superlative switch fabrics that encourage growth – the products that we hand-select from our vendors empower our customers with limitless potential,” says Jacobsz. 

Focusing on SDN, he highlights the vendor partnership with Mellanox, a leading supplier of end-to-end Ethernet and InfiniBand intelligent interconnect solutions and services for servers, storage, and hyper-converged infrastructure. 

“We view Mellanox as today’s network guru and are most impressed with the company’s take on SDN solutions for data centres, especially as it recognises that SDN is often an essential part of building cloud – both private and public clouds,” notes Jacobsz. 

A white paper by Mellanox, Software defined networking, done right, states: “Conceptually, SDN decouples the control and data planes, and logically centralises network intelligence and control in software-based controllers that maintain a global view of the network. This enables more streamlined policy-driven external control and automation from applications, which ultimately enhances network programmability and simplifies network orchestration.” 

The paper also highlights that there are three different deployment models dominating today’s SDN landscape. It lists these as: 

1.        Device-based SDN deployment model: In this model, the SDN controller uses a south-bound device control protocol to directly communicate policy or forwarding table information to the physical and virtual switching and routing devices. OpenFlow is the most commonly used protocol, and some of the early SDN architectures are based on OpenFlow to decouple control plane from network devices. 

2.        Overlay SDN deployment model: Many customers have an installed base of networking equipment that is not yet OpenFlow-enabled, and doing a network-wide upgrade may not be an option. Overlay approach of SDN deployment model came into being to bring SDN/ network virtualisation to these customers without requiring a forklift network upgrade that can be both expensive and disruptive to business services. Overlay SDN has been the most commonly seen architecture, and mainstream SDN solutions such as VMware NSX, Nuage Networks (now part of Nokia) VSP, PLUMGrid ONS, OpenContrail and Midokura MidoNet all primarily follow this model. 

3.        Proprietary SDN solutions: There are other proprietary SDN solutions in the market, such as Cisco Application Centric Infrastructure (ACI), Plexxi and Pluribus. With these solutions, the SDN controller and the SDN switching and routing elements are often tightly coupled. This category of SDN solutions is not as open as the above two, and it poses limitations for ecosystem vendors to integrate with them. 

“SDN is an evolving technology, and Mellanox currently works with only open SDN solutions,” points out Jacobsz. “We are therefore extremely confident when offering our customers the Mellanox solution that encompasses the most comprehensive, flexible and efficient SDN support through its end-to-end interconnect and associated software.” 

For more information on building the most efficient SDN networks, please contact Chris Coetzee, product manager: Mellanox at Networks Unlimited, at 



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