This object contains the next appropriate value to be used for fsTunnelAttributeIndex when creating entries in the fsTunnelAttributeTable.If the number of unassigned entries is exhausted, a retrieval operation will return a value of 0. When the SET is performed to create a row in the fsTunnelAttributeTable, the Command Responder (agent) must determine whether the value is indeed still unused; Two Network Management Applications may attempt to create a row (configuration entry) simultaneously and use the same value. If it is currently unused, the SET succeeds and the Command Responder (agent) changes the value of this object, according to an implementation-specific algorithm. If the value is in use, however, the SET fails. The Network Management Application must then re-read this variable to obtain a new usable value.