Delivery Rate Estimation
This document describes a generic algorithm for a transport protocol sender to estimate the current delivery rate of its data. At a high level, the algorithm estimates the rate at which the network delivered the most recent flight of outbound data packets for a single flow. In addition, it tracks whether the rate sample was application-limited, meaning the transmission rate was limited by the application rather than the congestion control algorithm. This algorithm can be implemented in any transport protocol that supports packet-delivery acknowledgment (thus far, open source implementations are available for TCP [RFC793] and QUIC [draft-ietf-quic-transport-00]).