This read-create enumerated value specifies the MPLS traffic-engineering tunnel metric type the IGP's enhanced SPF calculation uses for this path, which can be absolute or relative to the underlying IGP-computed cost. It lets an administrator control whether the tunnel's route-influencing metric is an outright replacement value or an adjustment relative to normal IGP cost. An operator wanting a tunnel to appear slightly cheaper than the native IGP path, without hardcoding an absolute number, would set csMplsPathMetricMode to relative(2) and configure a corresponding negative csMplsPathMetricValue.