Universitaet Karlsruhe Universitaet Karlsruhe This document specifies properties and characteristics of a Limited Effort (LE) per-hop behavior (PHB) for use within and between Differentiated Services domains [1]. The primary objective of this LE PHB is to protect best-effort (BE) traffic (packets forwarded with the default PHB) from LE traffic in congestion situations, i.e., when resources become scarce.