This object sets the delay metric value of this circuit for Level 2 traffic, where zero indicates the metric isn't supported. Administrators use this the same way as the Level 1 delay metric but for backbone traffic traversing this circuit. For example, an engineer sets a nonzero csIsisCircL2DelayMetric on a long-haul backbone circuit with noticeable propagation delay, reflecting that latency to delay-aware Level 2 path selection.