An entry in the data path table indicates the start of a single Differentiated Services Functional Data Path in this device. These are associated with individual interfaces, logical or physical, and therefore are instantiated by ifIndex. Therefore, the interface index must have been assigned, according to the procedures applicable to that, before it can be meaningfully used. Generally, this means that the interface must exist. When diffServDataPathStorage is of type nonVolatile, however, this may reflect the configuration for an interface whose ifIndex has been assigned but for which the supporting implementation is not currently present.