High Availability or HA is of the utmost importance to enterprise WANs today. If WAN resources are down, productivity screeches to a halt, and as goes productivity so goes profitability. If systems are inaccessible, no work gets done, customers are left dissatisfied, and a domino effect of bad outcomes begins.
Given that, it is no wonder that enterprises value failover, load balancing and high availability features when selecting a WAN connectivity solution. In recent years, SD-WAN has become the WAN solution of choice for a number of enterprises, so it’s no wonder that HA in SD-WAN has become a popular topic. Cloud-based, premium SDWaaS (SD-WAN as a Service) is one of the most robust and resilient forms of SD-WAN due in large part to a number of HA features that are baked in to the service.
In this piece, we will dive into some of the most important HA features of SDWaaS and explain how they can help your enterprise maximize uptime in a way that is easy to maintain and scale.
A Robust Global Private Network
To begin to understand the HA benefits of premium, cloud-based SDWaaS, it is useful to start with an understanding of its backbone. Premium SDWaaS providers have multiple Points of Presence (PoPs) across the globe which are connected by multiple Tier 1 ISPs (Internet Service Providers). If one PoP experiences an issue, service can be routed through another. By design, this network of PoPs is inherently robust and resilient. Further, premium cloud-based SDWaaS performance is backed by SLAs that enterprises can trust.
This means that in addition to the inherent redundancy made possible by SD-WAN because of the technologies inherently agnostic approach to the underlying transport method (e.g. ADSL, cable, 4G LTE, etc.), enterprises can benefit from a robust, high-performance, and highly available private network to route their WAN traffic. Further, the cloud-based nature of premium SDWaaS enables providers to effectively integrate security (another important, and often overlooked aspect of HA) directly into the service.
Self-Monitoring, Self-Healing & ILMM
If you’ve worked more than a day in IT or as a full stack engineer, it’s likely that you know things will inevitably go wrong. This is as true in the world of enterprise WAN as it is elsewhere. For this reason, premium SDWaaS providers have built self-monitoring, self-healing, and Intelligent Last Mile Management (ILMM) into SDWaaS.
Self-monitoring and self-healing are effectively what they say on the tin: solutions that automate the process of problem detection and failover. By automatically detecting and recovering from WAN connectivity issues, self-monitoring and self-healing help ensure that HA objectives are met while minimizing the need for manual intervention.
ILMM is a recent advancement in SDWaaS that helps solve “last mile problems” by taking a modern, automatic, and granular approach to last mile monitoring. Legacy SD-WAN solutions often only used ICMP (ping) monitoring of a router at an ISP or similar endpoint, however this left enterprises effectively blind to brownouts and other performance issues that could impact uptime and overall WAN performance. With ILMM, enterprises gain the benefits of last-mile profiling (to set performance baselines), infrastructure service (e.g. DNS, HTTP, etc.) monitoring, and pinpoint problem identification that allow for a quicker mean time to resolution for WAN issues.
Auto Updating Of Security Rules During Failover
One of the most compelling benefits of premium SDWaaS is that there is a full network security stack built into the network infrastructure. Not only does this make premium SDWaaS a holistic WAN solution, it helps enable scalable HA as security rules can be automatically updated if a failover occurs. With the traditional paradigm, when a failover occurred, security rules often had to be updated by a security engineer to avoid conflicts with the new IP addresses. With premium SDWaaS, since the firewall and security are built into the network, security rules and polices are automatically updated when a failover occurs. This helps to ensure maximum uptime, without compromising security.
Ability To Perform During Backbone Failures
In the highly unlikely (given the backbone is supported by multiple Tier-1 ISPs) event that an SDWaaS backbone fails, premium providers offer on-premises appliances that can “find” one another and use DTLS (Datagram Transport Layer Security) to authenticate and create an ad-hoc network between the appliances. This means that in addition to contingencies and fail-safes built into SDWaaS backbone, enterprises have a contingency in case the backbone itself goes down. Further, the appliances themselves have built in redundancy and HA features such as dual power supplies, clustering (both active/active and active/passive), and more.
SDWaaS Can Increase Uptime And Wan Resilience
Premium SDWaaS is uniquely capable of enabling enterprises to ensure that their WAN infrastructure achieves true high availability. HA features like self-healing, ILMM, and appliances that can maintain service if the backbone fails add a layer of resilience to an already robust private network and help maximize WAN uptime.