ISO 20794-3:2020

This document specifies the OSI transport layer and network layer by means of services and protocols. They can be used by different applications.
The transport layer:
-  transforms a message into a single packet;
-  adds protocol control information for diagnostic and node configuration into each packet;
-  adds packet identifier for diagnostic and node configuration into each packet; and
-   performs transport protocol error detection.
The transport layer protocol is not used for normal communication except to map the service interface parameters between lower and upper OSI layers.
The network layer:
-   adds a node address for diagnostic and node configuration into each segment; and
-   observes timing for diagnostic and node configuration of each segment.
The network layer is not used for normal communication except to map the service interface parameters between lower and upper OSI layers.