Huawei Technologies Huawei Technologies This document defines a collection of common common data types, identities, and groupings in the YANG data modeling language. These derived common common data types, identities, and groupings are intended to be imported by modules that model Layer 1 configuration and state capabilities. The Layer 1 types are representative of Layer 1 client signals applicable to transport networks, such as Optical Transport Networks (OTN). The Optical Transport Network (OTN) data structures are included in this document as Layer 1 types.