Quality of Service
QoS Advanced Mode
432 Cisco 350, 350X and 550X Series Managed Switches, Firmware Release 2.4, ver 0.4
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The 2 Rate 3 Color (2R3C) feature is supported on the device. In this feature, every 
policer has two thresholds. If the first threshold is reached, a user-configured Exceed 
action is performed. If the second threshold is reached, a user-configured Violate 
action is performed (see Aggregate Policer).
• Per flow QoS are applied to flows by binding the policies to the desired ports. A policy 
and its class maps can be bound to one or more ports, but each port is bound with at 
most one policy.
Notes:
• Single policer and aggregation policer are available when the device is in Layer 2 
mode.
• An ACL can be configured to one or more class maps regardless of policies.
• A class map can belong to only one policy.
• When a class map using single policer is bound to multiple ports, each port has its own 
instance of single policer; each applying the QoS on the class map (flow) at a port 
independent of each other.
• An aggregate policer applies the QoS to all its flow(s) in aggregation regardless of 
policies and ports.
Advanced QoS settings consist of three parts:
• Definitions of the rules to match. All frames matching a single group of rules are 
considered to be a flow. 
• Definition of the actions to be applied to frames in each flow that match the rules. 
• Binding the combinations of rules and action to one or more interfaces. 
Workflow to Configure Advanced QoS Mode 
To configure Advanced QoS mode, perform the following:
1. Select Advanced mode for the system by using the QoS Properties page. Select the Trust 
Mode using the Global Settings page. If a packet CoS level and DSCP tag are mapped to 
separate queues, the Trust mode determines the queue to which the packet is assigned:
• If internal DSCP values are different from those used on incoming packets, map the 
external values to internal values by using the Out-of-Profile DSCP Remarking page. 
This in turn opens the DSCP Remarking page. 
2. Create ACLs, as described in Create ACL Workflow.