If the application program supports parallel sessions, each session can use a different class-of-service entry and can map to a route that uses a different channel path.

For example, in Figure 1, because the type 2.1 peripheral node is connected to an NCP with parallel channel-link transmission groups (TG1 and TG2), the independent logical unit (APPL21) can establish parallel sessions with CICS® in the host, and each session can use a different route. However, each session must use a different Class of Service entry (such as COS1 and COS2). These different Class of Service entries map to different virtual routes (such as VR1 and VR2) using the same or different transmission priorities (in this case, the same, TP1). As shown in Figure 1, the different virtual routes map to the explicit routes for each session.

Figure 1. Parallel sessions using parallel transmission groups