Glossary 862 N Name Binding Protocol (NBP) An Apple protocol responsible for keeping track of entities on the network and matching names with Internet addresses. It works at the transport layer of the OSI reference model. namespace A set of unique names for resources or items used in a shared computing environment. For MMC, the namespace is represented by the console tree, which displays all of the snap-ins and resources that are accessible to a console. See also console tree; MMC; resource; snap-in. For DNS, namespace is the vertical or hierarchical structure of the domain name tree. For example, each domain label, such as host1 or example, used in a fully qualified domain name, such as host1.example.microsoft.com, indicates a branch in the domain namespace tree. narrowband (single-frequency) transmission High-frequency radio transmission similar to broadcasting. The user tunes both the transmitter and the receiver to a certain frequency to send and receive data. NAS (network access server)