aal1 Ces Service Type

This attribute specifies the service type for the CES. In an unstructured service, the entire data stream at the service interface (including any framing bits which may be present) is passed across the network transparently. The unstructured service uses the Unstructured Data Transfer (UDT) mode of AAL1. In a structured service, an Nx64kbit/s fraction of the data stream at the service interface is passed across the network. Two modes of structured service are supported: basicStructured and casStructured. In a casStructured service, the Channel Associated Signalling (CAS) bits are carried in a separate data structure from the Nx64 payload; in a basicStructured service they are not. The structured service uses the Structured Data Transfer (SDT) mode as defined in ITU-T Recommendation I.363.1. The serviceType attributes at both ends of a connection must be the same.