Install Guide

available. In this case, the system writes as many entries as possible, and then generates an CAM-full error message (shown in
the following example). The partial policy-map configuration might cause unintentional system behavior.
%EX2YD:12 %DIFFSERV-2-DSA_QOS_CAM_INSTALL_FAILED: Not enough space in L3
Cam(PolicyQos) for class 2 (TeGi 12/20) entries on portpipe 1
The test cam-usage command allows you to verify that there are enough available CAM entries before applying a policy-map
to an interface so that you avoid exceeding the QoS CAM space and partial configurations. This command measures the size of
the specified policy-map and compares it to the available CAM space in a partition for a specified port-pipe.
Test the policy-map size against the CAM space for a specific port-pipe or all port-pipes using these commands:
● test cam-usage service-policy input policy-map {stack-unit } number port-set number
● test cam-usage service-policy input policy-map {stack-unit } all
The output of this command, shown in the following example, displays:
● The estimated number of CAM entries the policy-map will consume.
● Whether or not the policy-map can be applied.
● The number of interfaces in a port-pipe to which the policy-map can be applied.
Specifically:
● Available CAM — the available number of CAM entries in the specified CAM partition for the specified line card or
stack-unit port-pipe.
● Estimated CAM — the estimated number of CAM entries that the policy will consume when it is applied to an interface.
● Status — indicates whether the specified policy-map can be completely applied to an interface in the port-pipe.
○ Allowed — indicates that the policy-map can be applied because the estimated number of CAM entries is less or equal
to the available number of CAM entries. The number of interfaces in the port-pipe to which the policy-map can be
applied is given in parentheses.
○ Exception — indicates that the number of CAM entries required to write the policy-map to the CAM is greater than
the number of available CAM entries, and therefore the policy-map cannot be applied to an interface in the specified
port-pipe.
NOTE:
The show cam-usage command provides much of the same information as the test cam-usage command,
but whether a policy-map can be successfully applied to an interface cannot be determined without first measuring how
many CAM entries the policy-map would consume; the test cam-usage command is useful because it provides this
measurement.
● Verify that there are enough available CAM entries.
test cam-usage
DellEMC# test cam-usage service-policy input pmap_l2 port-set 0 | port pipe
Port-pipe | CAM Partition | Available CAM | Estimated CAM | Status
=====================================================================
0 L2ACL 500 200 Allowed(2)
Specifying Policy-Based Rate Shaping in Packets Per
Second
You can configure the rate shaping in packets per second (pps) for QoS output policies.
You can configure rate shaping in pps for a QoS output policy, apart from specifying the rate shaping value in bytes. You can
also configure the peak rate and the committed rate for packets in kilobits per second (Kbps) or pps.
Committed rate refers to the guaranteed bandwidth for traffic entering or leaving the interface under normal network
conditions. When traffic propagates at an average rate that is less than or equal to the committed rate, it is considered to
be green-colored or coded. When the transmitted traffic falls below the committed rate, the bandwidth, which is not used
by any traffic that is traversing the network, is aggregated to form the committed burst size. Traffic is considered to be
green-colored up to the point at which the unused bandwidth does not exceed the committed burst size.
Peak rate refers to the maximum rate for traffic arriving or exiting an interface under normal traffic conditions. Peak burst size
indicates the maximum size of unused peak bandwidth that is aggregated. This aggregated bandwidth enables brief durations of
burst traffic that exceeds the peak rate and committed burst.
Quality of Service (QoS)
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