Configuring PFC QoS
The valid range of values for the pir bits_per_second parameter is as follows:
•
(Optional) You can specify a conform action for matched in-profile traffic as follows:
•
Note
(Optional) For traffic that exceeds the CIR, you can specify an exceed action as follows:
•
Note
Note
Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
41-64
–
The minimum token bucket size is 1 kilobyte, entered as 1000 (the maximum_burst_bytes
parameter must be set larger than the normal_burst_bytes parameter).
–
The maximum token bucket size is 512 megabytes, entered as 512000000.
To sustain a specific rate, set the token bucket size to be at least the rate value divided by 4000
–
because tokens are removed from the bucket every 1/4000th of a second (0.25 ms).
–
Because the token bucket must be large enough to hold at least one frame, set the parameter
larger than the maximum size of the traffic being policed.
For TCP traffic, configure the token bucket size as a multiple of the TCP window size, with a
–
minimum value at least twice as large as the maximum size of the traffic being policed.
Minimum—32 kilobits per second, entered as 32000 (the value cannot be smaller than the
–
CIR bits_per_second parameters)
Maximum with Release 12.2(18)SXE and later releases:
–
10 gigabits per second, entered as 10000000000
Maximum with releases earlier than Release 12.2(18)SXE:
–
4 gigabits per second, entered as 4000000000
The default conform action is transmit, which sets the policy map class trust state to trust
–
DSCP unless the policy map class contains a trust command.
To set PFC QoS labels in untrusted traffic, enter the set-dscp-transmit keyword to mark
–
matched untrusted traffic with a new DSCP value or enter the set-prec-transmit keyword to
mark matched untrusted traffic with a new IP precedence value. The set-dscp-transmit and
set-prec-transmit keywords are only supported for IP traffic. PFC QoS sets egress ToS and
CoS from the configured value.
–
Enter the drop keyword to drop all matched traffic.
When you configure drop as the conform action, PFC QoS configures drop as the exceed
action and the violate action.
–
The default exceed action is drop, except with a maximum_burst_bytes parameter (drop is not
supported with a maximum_burst_bytes parameter).
When the exceed action is drop, PFC QoS ignores any configured violate action.
Enter the policed-dscp-transmit keyword to cause all matched out-of-profile traffic to be
–
marked down as specified in the markdown map.
When you create a policer that does not use the pir keyword and the maximum_burst_bytes
parameter is equal to the normal_burst_bytes parameter (which is the case if you do not enter
the maximum_burst_bytes parameter), the exceed-action policed-dscp-transmit keywords
cause PFC QoS to mark traffic down as defined by the policed-dscp max-burst markdown
map.
Chapter 41
Configuring PFC QoS
OL-4266-08