CLI Reference Guide

Chapter 21 | Quality of Service Commands
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When a packet of size B bytes arrives at time t, the following happens if trTCM is
configured to operate in color-aware mode:
■
If the packet has been precolored as red or if Tp(t)-B < 0, the packet is red,
else
■
if the packet has been precolored as yellow or if Tc(t)-B < 0, the packet is
yellow and Tp is decremented by B, else
■
the packet is green and both Tp and Tc are decremented by B.
◆ The trTCM can be used to mark a IP packet stream in a service, where different,
decreasing levels of assurances (either absolute or relative) are given to packets
which are green, yellow, or red. Refer to RFC 2698 for more information on
other aspects of trTCM.
Example
This example creates a policy called “rd-policy,” uses the class command to specify
the previously defined “rd-class,” uses the set phb command to classify the service
that incoming packets will receive, and then uses the police trtcm-color-blind
command to limit the average bandwidth to 100,000 Kbps, the committed burst
rate to 4000 bytes, the peak information rate to 1,000,000 kbps, the peak burst size
to 6000, to remark any packets exceeding the committed burst size, and to drop
any packets exceeding the peak information rate.
Console(config)#policy-map rd-policy
Console(config-pmap)#class rd-class
Console(config-pmap-c)#set phb 3
Console(config-pmap-c)#police trtcm-color-blind 100000 4000 100000 6000
conform-action transmit exceed-action 0 violate-action drop
Console(config-pmap-c)#
set cos This command modifies the class of service (CoS) value for a matching packet (as
specified by the match command) in the packet’s VLAN tag. Use the no form to
remove this setting.
Syntax
[no] set cos cos-value
cos-value - Class of Service value. (Range: 0-7)
Default Setting
None
Command Mode
Policy Map Class Configuration
Command Usage
◆ The set cos command is used to set the CoS value in the VLAN tag for matching
packets.