Advertising In-situ Flow Information Telemetry (IFIT) Capabilities in BGP

In-situ Flow Information Telemetry (IFIT) refers to network OAM data plane on-path telemetry techniques, in particular In-situ OAM (IOAM) and Alternate Marking. This document defines a new Characteristic to advertise the In-situ Flow Information Telemetry (IFIT) capabilities. Within an IFIT domain, the IFIT capabilities advertisement from the tail node to the head node assists the head node to determine whether a particular IFIT Option type can be encapsulated in data packets. Such advertisement helps mitigating the leakage threat and facilitating the deployment of IFIT measurements on a per-service and on-demand basis.