Intelligent tunnel assignment and dynamic SLA threshold configuration to increase availability and utilization of SD-WAN tunnels

An apparatus, comprising:

• one or more network interfaces to communicate with a software defined wide area network (SD-WAN);
• a processor coupled to the network interfaces and configured to execute one or more processes;
• and
• a memory configured to store a process executable by the processor, the process when executed configured to:
• track a performance metric for a tunnel in the SD-WAN;
• compute a cumulative distribution function (CDF) for the tracked performance metric;
• assess curvature of the CDF for the tracked performance metric relative to a service level agreement (SLA) threshold of an application for that performance metric;
• and
• control assignment of traffic for the application to the tunnel, based on the assessed curvature of the CDF for the tracked performance metric relative to the SLA threshold of the application for that performance metric,
• wherein the apparatus assesses the curvature of the CDF for the tracked performance metric relative to the SLA threshold of the application for that performance metric by:
• computing a point of slope increase on the CDF;
• and
• determining a distance between the computed point of slope increase on the CDF and the SLA threshold of the application for that performance metric, wherein the computed point of slope increase on the CDF is either above or below the SLA threshold.

A tangible, non-transitory, computer-readable medium storing program instructions that cause a supervisory service for a software defined wide area network (SD-WAN) to execute a process comprising:

• tracking, by the supervisory service for the SD-WAN, a performance metric for a tunnel in the SD-WAN;
• computing, by the supervisory service, a cumulative distribution function (CDF) for the tracked performance metric;
• assessing, by the supervisory service, curvature of the CDF for the tracked performance metric relative to a service level agreement (SLA) threshold of an application for that performance metric;
• and
• controlling, by the supervisory service, assignment of traffic for the application to the tunnel, based on the assessed curvature of the CDF for the tracked performance metric relative to the SLA threshold of the application for that performance metric
• wherein the assessing of the curvature of the CDF for the tracked performance metric relative to the SLA threshold of the application for that performance metric comprises:
• computing, by the supervisory service, a point of slope increase on the CDF;
• and
• determining, by the supervisory service, a distance between the computed point of slope increase on the CDF and the SLA threshold of the application for that performance metric, wherein the computed point of slope increase on the CDF is either above or below the SLA threshold.