Fast and On-demand Network-wide Telemetry via Cluster Based Path Planning

In-band Network Telemetry (INT) has profoundly promoted the network visibility. However, the existing solutions either face Maximum Transmission Unit (MTU) limitation or latency issue due to continuous insertion of INT metadata along long forwarding paths. In addition, conducting telemetry using user packets is prone to result in duplicate telemetry and fall short to achieve network-wide telemetry. In this work, we propose NetworkSight to comprehensively resolve these problems through cluster based path planning and source routing based on-demand forwarding. Specifically, a cluster based path planning algorithm is designed to generate several balanced short forwarding paths that cover the entire network. As a consequence, the MTU limitation is overcome and the telemetry latency can be reduced. Instead of operating on user packets, NetworkSight sends crafted probes built on source routing to travel synchronously over the generated forwarding paths. With these improvements, network-wide telemetry is achieved. Besides, we define a suite of telemetry primitives and develop corresponding APIs for users to flexibly express their telemetry requirements. Extensive experimental results show that NetworkSight can generate more balanced forwarding paths. The results show that it outperforms state-of-the-art mechanisms, where it reduces the telemetry latency by tens of milliseconds.