On the platform 9010, we are using nested policers in this fashion:
Parent policer
policy-map 100M_TEST
class class-default
service-policy TEST_GOLD_T6
police rate 100 mbps
child-conform-aware
conform-action transmit
exceed-action drop
end-policy-map
Child policer
policy-map TEST_GOLD_T6
class VOICE_IN
police rate percent 25 burst 1500 ms peak-burst 3000 ms
conform-action set qos-group 5
conform-action set mpls experimental imposition 5
exceed-action drop
!
priority level 1
!
<snipped>
AS per the documentation, I am using Bc= CIR *(1/8)*1.5. The value in the output does not reconcile with the formula.
If we configure the burst value as 4687500 bytes (instead of 1500m ) in the policy, still in the router, Bc value is 312500 bytes.
show qos interface bundle-Ether 20.70 input
Interface: TenGigE0_0_0_2 input
Bandwidth configured: 10000000 kbps Bandwidth programed: 10000000 kbps
ANCP user configured: 0 kbps ANCP programed in HW: 0 kbps
Port Shaper programed in HW: 0 kbps
Policy: 100M_TEST Total number of classes: 5
----------------------------------------------------------------------
Level: 0 Policy: 100M_TEST Class: class-default
QueueID: N/A
Coupled parent policer
Policer Profile: 75 (Single)
Conform: 100000 kbps (100 mbps) Burst: 1250000 bytes (0 Default)
----------------------------------------------------------------------
Level: 1 Policy: TEST_GOLD_T6 Class: VOICE_IN
Parent Policy: 100M_TEST Class: class-default
QueueID: 262144 (Port Priority 1)
Coupled child policer
Policer Profile: 76 (Single)
Conform: 25000 kbps (25 percent) Burst: 3125000 bytes (1500 ms)
Child Policer Conform: set qos-grp 5 set exp-imp 5
Child Policer Exceed: DROP
Child Policer Violate: DROP
Can you please explain how this is calculated? Does my parent policer need a configuration change? (The default Bc of the parent is 100 ms?)
Here I assume that the maximum burst of the child policer is 1000ms( this is the only value which makes sense regarding the burst size).
Thanks