Cisco Systems OL-4266-08 manual 42-78

Chapter 42 Configuring PFC QoS

Configuring PFC QoS

Note The flowmask requirements of microflow policing, NetFlow, and NetFlow data export (NDE) might conflict.

•The valid range of values for the CIR bits_per_second parameter is as follows:

–Minimum—32 kilobits per second, entered as 32000

–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 normal_burst_bytes parameter sets the CIR token bucket size.

•The maximum_burst_bytes parameter sets the PIR token bucket size (not supported with the flow keyword)

•When configuring the size of a token bucket, note the following information:

–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 32 megabytes, entered as 32000000

–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.

•(Not supported with the flow keyword.) The valid range of values for the pir bits_per_second parameter is as follows:

–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

•(Optional) You can specify a conform action for matched in-profile traffic as follows:

–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, you can enter the set-dscp-transmitkeyword to mark matched untrusted traffic with a new DSCP value or enter the set-prec-transmitkeyword to mark matched untrusted traffic with a new IP precedence value. The set-dscp-transmitand set-prec-transmitkeywords are only supported for IP traffic. PFC QoS sets egress ToS and CoS from the configured value.

–You can enter the drop keyword to drop all matched traffic.

–Ensure that aggregate and microflow policers that are applied to the same traffic each specify the same conform-action behavior.

	Cisco 7600 Series Router Cisco IOS Software Configuration Guide, Release 12.2SX
42-78	OL-4266-08