Reports, as a string, the cumulative total number of packets this Virtual System has processed. Since it's per-tenant, this is the throughput figure used for usage-based billing or capacity comparisons between tenants sharing the same VSX chassis, distinct from the chassis-wide packet counters elsewhere in the MIB. Example: comparing vsxCountersPackets across three tenants on the same chassis over a billing period reveals which one is actually driving most of the shared hardware's load.