In the electrical-layer structure of OTN, which of the following Is the path layer sequence...

The electrical-layer structure of OTN frames follows the path: OTUk → ODUk → OPUk → Client. OTUk is the outer frame layer that carries ODUk (Optical Data Unit), which in turn contains OPUk (Optical Payload Unit). The OPUk holds the client signal payload. This hierarchical encapsulation supports transparent transport of client signals over optical networks. Understanding this sequence is essential for managing signal mapping and monitoring in OTN networks as outlined in HCIP-Transmission documentation.