Description: This attribute indicates the name of a possible route request data parameter which prevents RouteSelector from selecting the route. This attribute always has a value of allAttributesMet for manual routes since RouteSelector does not verify manual routes. This attribute has a meaningful value if reasonForNoRoute attribute has a value of attributesNotMet. The value of attributeNotMet is only computed when RouteSelector operates in manual mode. That is, when route selection has been initiated by the operator in which case operationMode has a value of manual.

RouteSelector determines which of the attributes: requiredRxBandwidth, requiredTxBandwidth, requiredTrunkModes, maximumAcceptableCost, maximumAcceptableDelay, maximumAcceptableGatewaCost, requiredTrafficType, permittedTrunkTypes, requiredSecurity, requiredCustomerParameter, and maximumTransmissionUnit prevents successful route selection by dropping the constraints associated with that attribute and reselecting the route. If that route can be successfully selected then the attribute for which the constraints were dropped is the attribute preventing successful route selection.

For example, RouteSelector drops bandwidth constraints by selecting a route with requiredRxBandwidth or requiredTxBandwidth of 0. If the route can be selected then bandwidth is preventing successful route selection.

A value of unknownAttributeNotMet indicates that RouteSelector cannot determine why route cannot be selected. Constraints for all attributes are dropped yet successful route cannot be computed. This usually indicates a lack physical connectivity to the destination or gateway node. Alternatively, this may indicate that destination or gateway node is more than 20 hops away where 20 hops is the maximum number of hops in the route.