Network Router User Manual

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