In the evolving world of Software-Defined Wide Area Networking (SD-WAN), ensuring seamless connectivity and uninterrupted service is crucial for businesses. One of the key aspects of this is achieving instantaneous fail-over when a network link goes down. While many SD-WAN products rely on probes or legacy router protocols to detect failures and reroute traffic, these methods often fall short in providing the necessary speed and reliability. Instead, using tunnels within SD-WAN architecture is the best approach to achieve true instantaneous fail-over.

The Problem with Probes & Legacy Protocols

Probes are commonly used in many SD-WAN solutions to monitor the health of network paths. These probes send periodic test packets to detect issues like packet loss, latency, or jitter. When a problem is detected, the SD-WAN solution will reroute traffic to a backup path. However, this approach has a significant drawback: latency in failure detection.

Since probes are sent at intervals, there is an inherent delay between the moment a failure occurs and when it is detected. This delay can lead to brief but impactful periods of service disruption, which can be detrimental to applications requiring real-time data transmission, such as VoIP, video conferencing, or online transactions.

Legacy router protocols like OSPF or BGP also face similar challenges. These protocols were not designed with the instantaneous fail-over needs of modern networks in mind. While they do eventually detect failures and reroute traffic, the convergence times can be slow, leading to noticeable service interruptions.

The Ethernet Problem | A Historical Perspective

The slow fail-over times often seen in modern networks can be traced back to the adoption of Ethernet for WAN connections. In the early days of networking, WAN links were primarily connected using serial devices. These devices had built-in signaling mechanisms that allowed routers to immediately detect a path failure and trigger a fail-over. This ensured a near-instantaneous response to network issues.

However, when Ethernet began to replace serial connections in WANs, these instantaneous signaling capabilities were lost. Ethernet, by design, does not provide the same level of immediate feedback when a path fails. As a result, failovers became slower and less reliable, relying on higher-level protocols to detect and respond to failures.

The Tunnel Advantage | Instantaneous Fail-over with Pseudo-wires

Tunnels offer a solution to the fail-over issues introduced by Ethernet. By using tunnels, SD-WAN solutions can create pseudo wires that effectively emulate the behavior of serial connections over Ethernet. These tunnels encapsulate data traffic, creating a virtual point-to-point link between network devices.

The key advantage of using tunnels is that they provide immediate feedback when a path fails. If the tunnel itself fails, the SD-WAN solution can instantly detect this and reroute traffic to an alternative tunnel without delay. This results in truly instantaneous fail-over, ensuring that service continuity is maintained even in the event of a network issue.

Real-World Example | Fusion SD-WAN vs. the Competition

An excellent example of this approach in action is Fusion SD-WAN. Unlike other SD-WAN solutions that rely on probes or slower fail-over mechanisms, Fusion SD-WAN uses tunnels to create robust and reliable connections across the WAN. This ensures that when a path fails, the system can immediately switch to a backup path, minimizing any disruption to the end-user experience.

In contrast, other products like Meraki or Fortinet rely on probes or similar methods to detect failures. These solutions often struggle with delayed fail-over times, leading to periods of reduced service quality or even complete outages. The difference in approach is clear: Fusion SD-WAN leverages tunnels to provide a level of resilience and reliability that competing solutions simply cannot match.

Wrap

In the world of SD-WAN, achieving instantaneous fail-over is critical for maintaining business continuity and ensuring a seamless user experience. While traditional methods like probes and legacy protocols have their place, they fall short in delivering the speed and reliability required by modern networks.

Tunnels, by creating pseudo wires over Ethernet, offer a superior alternative that allows for immediate detection and response to network failures. Solutions like Fusion SD-WAN, which embrace this approach, provide a significant advantage in terms of resilience and reliability, ensuring that businesses can stay connected and operational even in the face of network challenges.

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Ronald Bartels ensures that Internet inhabiting things are connected reliably online at Fusion Broadband South Africa - the leading specialized SD-WAN provider in South Africa. Learn more about the best SD-WAN provider in the world! 👉 Contact Fusion