A method for isolating packet loss on a hierarchical packet network, the method including: connecting a first network element (NE) to a second NE via a varying path traversing multiple network segments; discovering, with the first NE, a set of segment-demarcation expect-to-echo nodes along the varying path; ascertaining, with the first NE, a request-to-echo configuration for each node in the set; emitting a sample size of requests-to-echo in a respective request-to-echo configuration for each node in the set at a sample rate; receiving results of the sample size of requests-to-echo to generate a packet-loss sample; and calculating a rate-of-loss for the packet-loss sample.