SD-WAN Redundancy with Cradlepoint
May 31, 2019
Often times we have customers that are highly concerned with uptime, requesting an active/active environment. While this isn’t an unusual request as most companies don’t consider “downtime” to be a preferred status, it requires a little more consideration. In order for a network to be high availability, it means every single point of failure has a redundancy point. In the case of an SD-WAN device, while downtime is highly uncommon, a single network device is a single point of failure.
This is an interesting position for a customer as placing a failover SD-WAN device at every single site, in addition to the production one, is not only an overspend of resources but of time, management, and ongoing maintenance/monitoring. While it’s not inconceivable that a customer would require this, for example, in a financial institution where downtime is literally unacceptable, there are other methods.
The team at QOS Networks has a unique talent for finding network solutions for complex network conundrums. We recently worked with a customer who needed a high availability environment without the duplication of their entire network stack at every single branch. The answer to that was utilizing a Cradlepoint LTE router as a backup to the SD-WAN (VeloCloud) edge appliance at each site.
What Did QOS Do?
With our team of expert engineers, we set to task to design a brilliant network automation system that will detect when an SD-WAN device goes down and provide failover using the Cradlepoint router. We combined network engineering techniques such as VRRP and redundant IPSec tunnels with the Cradlepoint NCOS application development platform and backend routing automation to create an intelligently healing edge network stack. If the SD-WAN device fails, the LTE device takes over, the SW-WAN overlay is rerouted and the solution effectively prevents extensive service interruptions.
This particular customer also wanted to take advantage of another SD-WAN benefit by having circuit diversity at each location, specifically with LTE and broadband. The dual-SIM Cradlepoint routers provide additional capability with wireless carrier diversity using both AT&T and Verizon. Blending these connection options with smart hardware failover gives the customer a highly robust edge network stack that can survive many of the most common trouble scenarios.
This solution solved more than just a high availability requirement, but helped to keep redundant costs down by providing the failover capability without the duplicate hardware layers. This kept the performance in place, allowed for circuit diversity across multiple carriers, and gave the customer the needed peace of mind that each point of failure had a backup plan.
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