VXLAN-based INT: In-band Network Telemetry for Overlay Network Monitoring

Overlay network protocols, such as VXLAN, are leveraged to address the need for network multiplexing and resource isolation within public clouds to accommodate multiple tenants. Since overlay networks are much more complex than underlay networks, overlay network monitoring is more significant and challenging. In-band Network Telemetry (INT) can achieve fine-grained network monitoring by encapsulating data plane states into probe packets. However, as an underlying device-level primitive, INT cannot be directly applied to overlay network monitoring given underlay networks and overlay networks are generally transparent from each other. In this work, we propose VXLAN-based INT, a telemetry system for overlay network monitoring based on VXLAN. By inserting the INT metadata collected from the underlay devices into the VXLAN payload, we successfully build the real-time overlay-underlay association at the controller, through which, one can easily localize the root cause of overlay path congestion within a simple database lookup.