WAN Failover

Overview

WAN failover is a critical feature, enabled by default on your Uplevel Gateway, that ensures your business stays connected to the internet even if your primary connection fails. This article explains how our WAN failover system works and how it keeps your network reliable and resilient.

How It Works (Simplified)

Think of WAN failover like having a backup generator for your internet connection.

• We monitor your primary internet connection using three servers distributed across different regions of the country
• If the monitor fails to reach all three servers for 5 consecutive checks, we automatically failover to your auxiliary internet connection
• While using the auxiliary connection, we keep checking your primary connection
• As soon as we detect that your primary connection is working again, we switch your traffic back to it
• We also monitor your auxiliary connection to ensure it's ready when needed
• For auxiliary connections with limited data plans (like LTE), we can reduce how often we check them to help conserve data

Technical Details

Our WAN failover system implements the following monitoring and switching protocol:

1. Health Check Protocol

   • Uplevel's WAN Manager performs TCP handshakes with three health check servers
   • The servers are distributed across different AWS regions for redundancy and to limit false positives
   • Health checks occur every second
   • If any handshake completes successfully, the connection is marked as "Up"
   • If handshakes fail to all three servers for 5 consecutive attempts, the connection is marked as "Down"

2. Failover Trigger

   • Failover occurs when the primary connection is marked as "Down"
   • The 5-second window helps prevent unnecessary switching due to brief connection hiccups
   • Both primary and secondary connections are monitored using this protocol

3. Continuous Monitoring

   • While operating on the secondary connection, the WAN manager continues to monitor the primary connection
   • A single successful health check response from the primary connection will trigger a switch back

4. Customizable Monitoring

   • For secondary connections with data caps (such as LTE backup connections), the health check frequency can be adjusted
   • This helps manage data usage while maintaining reliable failover capabilities

Best Practices

• Ensure both primary and auxiliary connections are from different ISPs to maximize redundancy
• For LTE auxiliary connections, consider adjusting the health check frequency based on your data plan
• Regularly test your failover setup to ensure it works as expected

Support

If you have questions about WAN failover setup, please contact our support team.