Figure 13 illustrates two Connections, each between two PubSubConnectionEndpoints. Each PubSubConnectionEndpoint on AC_A (and similarly on AC_B) references a DataSetWriter (and DataSetReader) that are located under the same WriterGroup (and ReaderGroup).
The PubSub instances are configured to exchange data between AC_A and AC_B using unicast NetworkMessages. This use case is called aggregated because a single NetworkMessage aggregates multiple DataSetMessages (one per logical connection). Aggregation reduces the required network bandwidth.