The VSR-NRC 1+1 redundancy features introduces a global channel between each VSR-NRC and the NRC-P for exchanging channel health and notification messages that are not application-specific.
Figure 1 illustrates the sequence of messages to establish the global health and notification channel as well as the sequence of messages used for establishing the VSR-NRC role of active or standby.
Figure 1. Global Health and Notification Channel Message Sequence
