This document describes behavior of signalling intermediaries in RTC deployments, sometimes referred to as Session Border Controllers (SBCs), when performing Hosted NAT Traversal (HNT). HNT is a set of mechanisms, such as media relaying and latching, that such intermediaries use to enable other RTC devices behind NATs to communicate with each other. This document is non-normative, and is only written to explain HNT in order to provide a reference to the IETF community, as well as an informative description to manufacturers, and users.