In the early days of programming, I embarked on my coding journey with a ZX81, a humble computer that introduced me to the fundamental logic of:

IF logical expression THEN procedure ELSE procedure

Back then, error handling was a crucial part of programming. We had limited memory (only 16KB!), but we still implemented error-handling routines diligently. Fast forward to the era of SD-WAN, where closed-loop automation has become the norm, and the importance of error handling remains just as critical. In this article, we'll delve into the world of SD-WAN, emphasizing the significance of exception handling, inspired by the lessons from the past.

ZX81: Where It All Began: The ZX81 was a rudimentary computing device, but it taught us a valuable lesson – error handling matters. While modern programmers often focus on making data match and overlook mismatches, we understood that robust programs needed to account for errors. Error handling wasn't just a luxury; it was a necessity. As we ventured into the digital frontier, these lessons stayed with us, even as our tools evolved.

SD-WAN: Beyond the Lab and into Reality: SD-WAN, the cutting-edge technology of today, relies on a set of conditions and associated actions. Exception handling, akin to error handling of the past, is essential in this context. However, in SD-WAN, we deal with three types of exceptions: loss, faults, and errors. Understanding and addressing these exceptions are fundamental to the well-known CIA security framework:

C = Confidentiality (related to loss) 
I = Integrity (related to errors) 
A = Availability (related to faults)

Loss: Protecting What's Yours: Loss, often associated with theft, is a common occurrence in the digital savannah. From last-mile cables to SD-WAN Customer Premises Equipment (CPE), vulnerabilities abound. Implementing IoT-based power management and inventory systems can help monitor and secure your infrastructure. Geo-tagging and smart SFPs can further enhance security and address cable break issues, ensuring your data remains confidential.

Errors: Averting Pitfalls: Errors can be insidious, affecting network performance and reliability. SD-WAN hardware can directly read error counters, allowing for swift determinations. For example, wireless connections may experience Bit Error Rates (BERs), which can be mitigated through queuing or alternative paths. Bandwidth adaptation mechanisms ensure that Quality of Service (QoS) calculations align with actual link capabilities, not perceived ones, enhancing data integrity.

Faults: Ensuring Uptime: In SD-WAN environments, both uplinks (carrier connections) and downlinks (client connections) must be monitored rigorously. Faults can occur on both sides, but the probability is higher on the client side. Fiber cables can bend or become unplugged, and equipment failures are not uncommon. Protocols designed for troubleshooting are invaluable for detecting and addressing faults, ensuring data availability.

Wrap: In the world of SD-WAN, it's not just about doing the job; it's about knowing when the job isn't being done and taking automated action. The lessons learned from the ZX81 era, where error handling was paramount, remain relevant in today's digital landscape. Exception handling in SD-WAN ensures data confidentiality, integrity, and availability, mirroring the principles of the CIA security framework.

In the immortal words of "Fuck Everything, Do Five Blades," the underlying function of SD-WAN isn't just to do the job but to detect when the job isn't being done and automatically mitigate. At Fusion Broadband South Africa, we embrace this philosophy, ensuring that your SD-WAN operates seamlessly in the real world, where exception handling is not just a concept but a necessity.

---

At Fusion Broadband South Africa , we understand the importance of error handling, exception management, and ensuring your SD-WAN operates seamlessly in the real world. In the spirit of collaboration, we welcome your contributions and insights in the comments.

---