Device-level virtual port utilization information.
Octet 0: average virtual port utilization over the latest sample period (percent)
Octet 1: average virtual port utilization over the latest minute (percent)
Octet 2: average virtual port utilization over the latest hour (percent)
Octet 3: maximum virtual port utilization over the latest hour (percent)
virtual port utilization = total active virtual ports / device virtual port capacity.