Network Router User Manual

A-20
Cisco 7304 Router MIB Specifications Guide
OL-4925-02
Appendix A Using MIBs
Monitoring Quality of Service
Considerations for Processing QoS Statistics
The router maintains 64-bit counters for most QoS statistics. However, some QoS counters are
implemented as a 32-bit counter with a 1-bit overflow flag. In the following figures, these counters are
shown as 33-bit counters.
When accessing QoS statistics in counters, consider the following:
• SNMPv2c or SNMPv3 applications—Access the entire 64 bits of the QoS counter through
cbQosxxx64 MIB objects.
• SNMPv1 applications—Access QoS statistics in the MIB as follows:
– Access the lower 32 bits of the counter through cbQosxxx MIB objects.
– Access the upper 32 bits of the counter through cbQosxxxOverflow MIB objects.
Sample QoS Statistics
This section shows how QoS statistics are displayed in show commands and stored in
CISCO-CLASS-BASED-QOS-MIB tables.
For ease-of-use, the display shows some counters as a single object even though the counter is
implemented as three objects. For example,
cbQosCMPrePolicyByte is implemented as:
cbQosCMPrePolicyByteOverflow
cbQosCMPrePolicyByte
cbQosCMPrePolicyByte64
Note Due to implementation features, some of the QoS statistics counters might wrap before they reach the
maximum value they can accommodate.
The following is a sample of QoS class map statistics.
class-map dscp16
match ip dscp 16
Ta b l e A- 4 Q o S S t a t i s t i c s Ta b l e s
QoS Table Statistics
cbQosCMStatsTable Class Map—Counts of packets, bytes, and bit rate before and
after QoS policies are executed. Counts of dropped packets and
bytes.
cbQosMatchStmtStatsTable Match Statement—Counts of packets, bytes, and bit rate before
executing QoS policies.
cbQosPoliceStatsTable Police Action—Counts of packets, bytes, and bit rate that
conforms to, exceeds, and violates police actions.
cbQosQueueingStatsTable Queueing—Counts of discarded packets and bytes, and queue
depths.
cbQosTSStatsTable Traffic Shaping—Counts of delayed and dropped packets and
bytes, the state of a feature, and queue size.
cbQosREDClassStatsTable Random Early Detection—Counts of packets and bytes dropped
when queues were full and also when transmitted.