In the following example, DELAY is still equal to t, but before t expires and after four messages arrive at the NCP, an outbound message (M') is sent form VTAM® to NCP. In this case, four messages are sent to the host with no attention interrupts generated. This is the ideal case, in terms of saving instructions executed in the host.

Figure 1. ATM configuration with a connection network

The sample XCA major nodes for the Connection Network follow. See Using XCA over an IBM S/390 OSA for connection network for the corresponding switched major nodes for the Connection Network.