AM-PM: Efficient Network Telemetry using Alternate Marking

The fast evolution of high-speed networks has raised the need for accurate and scalable network measurement. Thus, in the last few years several new methods to collect network state information have been pursued by network operators and vendors across the board. This article focuses on the AM-PM approach, which allows accurate measurement of performance metrics, including packet loss and delay, using two bits or less in the header of each packet. This method was documented and recently published as an RFC by the IETF [RFC 8321]. This article provides an overview of AM-PM and how it can be applied in practice. The article also shares operational experience from a large-scale deployment and presents experimental results from an implementation of the AM-PM method.