Cisco SG500X-24 - Page 515

Quality of Service
QoS Advanced Mode
497 Cisco 500 Series Stackable Managed Switch Administration Guide Release 1.3
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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.
For example: Assume that there are three levels of service: Silver, Gold, and
Platinum and the DSCP incoming values used to mark these levels are 10, 20, and
30 respectively. If this traffic is forwarded to another service provider that has the
same three levels of service, but uses DSCP values 16, 24, and 48, Out of Profile
DSCP Mapping changes the incoming values as they are mapped to the outgoing
values.
To m a p D S C P v a l u e s :
STEP 1 Click Quality of Service > QoS Advanced Mode > Out of Profile DSCP Mapping.
This page enables setting the change-the-DSCP-value of traffic entering or
leaving the device.
DSCP In displays the DSCP value of the incoming packet that needs to be re-
marked to an alternative value.
STEP 2 Select the DSCP Out value to where the incoming value is mapped.
STEP 3 Click Apply. The Running Configuration file is updated with the new DSCP
Mapping table.