This monitor tracks the aggregated network usage of the whole cluster. The value is calculated by adding the network byte/sec throughput values of all nodes.
Sustained high network usage is usually caused by jobs that send an excessive number of messages between nodes. If network throughput usage is close to the maximum network capacity, then jobs, especially MPI jobs, may take longer to complete.
Use job policies to manage the load. You can also use a network that has greater amount of throughput to increase the capacity of the cluster.