Cisco 350XG series Administration Manual page 593

Quality of Service
QoS Advanced Mode
Cisco 350XG & 550XG Series 10G Stackable Managed Switches
• A policy contains one or more class maps.
• A class map defines a flow with one or more associating ACLs. Packets that
match only ACL rules (ACE) in a class map with Permit (forward) action are
considered belonging to the same flow, and are subjected to the same
quality of services. Thus, a policy contains one or more flows, each with a
user defined QoS.
• The QoS of a class map (flow) is enforced by the associating policer. There
are two type of policers, single policer and aggregate policer. Each policer
is configured with a QoS specification. A single policer applies the QoS to a
single class map, and thus to a single flow, based on the policer QoS
specification. An aggregate policer applies the QoS to one or more class
maps, and thus one or more flows. An aggregate policer can support class
maps from different policies.
• 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.
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