Arbor Networks Ericsson HTT Consulting Verisign Huawei NTT Communications The DDoS Open Threat Signaling (DOTS) effort is intended to provide a protocol that facilitates interoperability between multivendor solutions/services. This document presents use cases to evaluate the interactions expected between the DOTS components as well as DOTS messaging exchanges. The purpose of describing use cases is to identify the interacting DOTS components, how they collaborate and what are the types of information to be exchanged.