Cisco 500 Series Administration Guide

Quality of Service
QoS Advanced Mode
Cisco 500 Series Stackable Managed Switch Administration Guide 620
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In QoS Advanced Mode, when the Default Mode Status is set to Not Trusted, the
default CoS values configured on the interface is ignored and all the traffic goes to
queue 1. See the Quality of Service > QoS Advanced Mode > Global Settings
page for details.
If you have a policy on an interface then the Default Mode is irrelevant, the action is
according to the policy configuration and unmatched traffic is dropped.
STEP 4 Select Override Ingress DSCP to override the original DSCP values in the
incoming packets with the new values according to the DSCP Override Table.
When Override Ingress DSCP is enabled, the device uses the new DSCP values
for egress queueing. It also replaces the original DSCP values in the packets with
the new DSCP values.
NOTE The frame is mapped to an egress queue using the new, rewritten
value, and not by the original DSCP value.
STEP 5 If Override Ingress DSCP was enabled, click DSCP Override Table to
reconfigure DSCP. See the DSCP Override Table page for details.
Configuring Out-of-Profile DSCP Mapping
When a policer is assigned to a class maps (flows), you can specify the action to
take when the amount of traffic in the flow(s) exceeds the QoS-specified limits.
The portion of the traffic that causes the flow to exceed its QoS limit is referred to
as out-of-profile packets.
If the exceed action is Out of Profile DSCP, the device remaps the original DSCP
value of the out-of-profile IP packets with a new value based on the Out of Profile
DSCP Mapping Table. The device uses the new values to assign resources and
the egress queues to these packets. The device also physically replaces the
original DSCP value in the out of profile packets with the new DSCP value.
To use the out-of-profile DSCP exceed action, remap the DSCP value in the Out Of
Profile DSCP Mapping Table. Otherwise the action is null, because the DSCP value
in the table remaps the packets to itself by factory default.
This feature changes the DSCP tags for incoming traffic switched between
trusted QoS domains. Changing the DSCP values used in one domain, sets the
priority of that type of traffic to the DSCP value used in the other domain to
identify the same type of traffic.
These settings are active when the system is in the QoS basic mode, and once
activated they are active globally.

Cisco 500 Series Specifications

General

Model	Cisco 500 Series
Category	Switch
Mounting	Rack-mountable
Management	Web-based, CLI, SNMP
Ports	24, 48
Port Speed	10/100/1000 Mbps
PoE Support	Available on some models
Switching Capacity	Up to 176 Gbps
MAC Address Table Size	16, 000 entries
Security	ACLs, 802.1X
Quality of Service (QoS)	Yes
Dimensions	Varies by model
Weight	Varies by model
Humidity	10% to 90% non-condensing
Power Supply	Internal
Power Consumption	Varies by model
Jumbo Frame Support	Up to 9216 bytes