🚸Demystifying SD-WAN: Debunking the Diverse Fiber Path Fallacy🤡

🚸Demystifying SD-WAN: Debunking the Diverse Fiber Path Fallacy🤡

Is buying fibre redundancy from the same operator such as Dark Fibre Africa addressing the problem of reduced outages?


3 min read

In the ever-evolving world of networking, misconceptions can linger like ghosts in the machine. I recently had a conversation with an ISP CEO who confidently asserted that SD-WAN was irrelevant. According to him, all you needed was a redundant fiber connection from an operator and a set of standard routing protocols to achieve network resilience. While there's some truth in his observation, especially in the context of data center interconnections, the closer you get to the customer's premises over the last mile, the less this argument holds water. In this article, we'll explore the diverse fiber path fallacy, dissecting the business and technical justifications that reveal it as a myth.

The Cost of Diversification: Let's begin with the economics. Diversifying your network with a redundant fiber path from the same operator might sound like a wise move, but in reality, you're paying double for a diverse path that covers only 20% of the fiber run. Here's the scenario: The operator has a point of presence (POP), and you have your customer premises. At your premises, a diverse fiber path is installed, with each fiber going in opposite directions on the street—a classic setup. However, within a street block, these diverse paths converge into the same conduit. In other words, there's a common path for an average of 80% of the distance of a fiber run.

Probability vs. Proximity: Statistically, the likelihood of a fault occurring is higher on the common path, which is longer than the diverse path. However, there's a catch. The areas around the operator's POPs tend to have higher industrial activity and construction work, increasing the likelihood of backhoes and other excavation equipment operating close to the POP. This means that despite the longer common path, the potential for disruption might be higher near the POP.

Reevaluating the Value Proposition: The true value of that extra path may not align with the price you pay for it. Instead, consider reallocating those funds to install a diverse path from an alternative fiber or wireless operator, rather than relying on the same operator with a diverse path. Fixed wireless emerges as an excellent choice as an alternative, offering potential last-mile protection for distances of at least 10 kilometers, compared to the mere city-block coverage of a fiber operator.

From Plain Old Telephones to Fiber: The fundamental principles haven't changed much since the days of plain old telephones. Telephone lines converged onto single paths as they traveled from customer premises through various street poles, exchanges, and regional hubs. Fiber operates on similar principles—it's not a magical unicorn.

Legacy Routing vs. SD-WAN: Suppose you're now convinced of the value of multiple fiber or wireless operators but are hesitant about adopting SD-WAN. You prefer sticking to the tried-and-tested legacy routing products and protocols you're familiar with. While you're in a better position, challenges persist.

Legacy protocols lack the ability to aggregate bandwidth across operators, and cut-over times between paths are measured in minutes, not milliseconds. SD-WAN seamlessly addresses these issues while adding quality of experience, traffic visibility, and security to the mix.

With SD-WAN, that second link is never a grudge purchase—it won't remain idle until needed. SD-WAN presents a compelling business case, offering cost justification and fulfilling technical requirements through advanced networking functionality.

Ronald ensures that Internet inhabiting things are connected reliably online at Fusion Broadband South Africa - the leading specialized SD-WAN provider in South Africa. 👉 Contact Fusion