Taking detours: An in-network fault-tolerant probing planning for In-band Network Telemetry

In-band Network Telemetry (INT) is a novel network monitoring approach mainly fostered by programmable network devices. Despite existing efforts toward the orchestration of INT, little has yet been done to provide fault-tolerant mechanisms in the data plane (e.g., to address hardware failure). In this paper, we introduce InPatching - an in-network approach to fast recover INT-based monitoring from network link failures. InPatching is implemented in the data plane and allows the application of detours in an autonomous and coordinated manner without the control plane intervention. To provide efficient detours to INT solutions, we formalize the fault-tolerant probing planning for INT by means of a MILP (Mixed-Integer Linear Programming) model. We prototype InPatching in P4 and we show that it can recover from fault conditions much faster than control plane solutions (up to 18X), while not imposing substantial overhead.