Two-Way Quality of Service Policy Enforcement Methods in Dynamically Formed Overlay Virtual Private Networks

Modern Virtual Private Networks (VPNs) are built over various last-mile connections. Physical data rates may not be aligned to customer contracted speed. This leads to traffic drops by the service provider when a customer sends traffic at line speed. VPN service over such lines may experience connection interruptions and packet loss and never converge in the worst-case scenario. Large enterprises use multiple VPN connections simultaneously over different transport networks. Each network may have different physical properties and requires separate Quality of Service (QoS) policy. It needs to be configured both ways, from customer to service provider and from service provider to customer. By using overlay VPN, customers can configure granular and symmetric QoS policies. This enables capacity planning and good quality of experience. For the FlexVPN solution, based on IKEv2 and IPSec technology, symmetric QoS is easily attainable and is suitable for large-scale deployments. Attributes can be locally stored or received from an external server. For configuration that needs to be manually applied on a large number of network devices, a network automation framework may be used to speed up configuration deployment and avoid misconfiguration issues. Nornir is one of the automation frameworks currently widely used for configuration deployment.