This part of 62056 specifies the transport layers for COSEM communication profiles for
use on IPv4 networks.
These communication profiles contain a connection-less and a connection-oriented transport
layer, providing OSI-style services to the service user COSEM application layer. The
connection-less transport layer is based on the Internet standard User Datagram Protocol.
The connection-oriented transport layer is based on the Internet standard Transmission
Control Protocol.
Although the major part of the COSEM transport layers is the UDP and TCP as they are
specified in the relevant Internet standards, they include an additional sub-layer, called
wrapper.
Annex A shows how the OSI-style transport layer services can be converted to and from UDP
and TCP function calls.