This read-only CoriantTypesOduType value reports the ODU type at multiplexing level 3, for services with a third layer of ODU nesting (for example a lower-rate ODUflex multiplexed inside an ODU2e that itself rides inside an ODU4). This gives operators visibility into deeper multiplexing hierarchies used for finer-grained bandwidth grooming. For example, odutypeL3 reading ODUflex would show that, three layers down, this path ultimately carries a flexible-rate client signal.