This INTEGER identifies exactly which instantiation of the queue-group profile is dedicated to this specific sub-port, since a profile can be instantiated multiple times across different sub-ports sharing one parent interface. This keeps each customer's actual queue occupancy and counters distinct even though they share the same profile template. This sub-port getting instance ID 7 of the shared profile, distinct from a neighboring customer's instance ID 8 of that same template on the same parent port, illustrates the separation.