Packet-Triggered Statistics Reporting for In-situ OAM

This document defines a packet-triggered statistics reporting extension for In-situ Operations, Administration, and Maintenance (IOAM). The extension specifies a 2-bit Cycle Identifier field that enables receiving nodes to trigger statistics reporting based on observed Cycle ID transitions in received packets. This document defines the Cycle ID field format, node processing procedures, and keepalive packet generation rules.