Cisco SPS208G User Manual page 159

QoS
SPS208G/SPS224G4/SPS2024 Service Provider Switches User Guide
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802. 1 p Port-based
forwarding untagged packets. Those packets can then pass in
accordance to the priority defined on that queue. Untagged packets can
also be converted into tagged packets, with their VPT defined
according to the device's active VPT mapping.
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Layer 3 Predefined Field — In this method, the DiffServ Code Point (DSCP)
of incoming packets are the basis for mapping the packets to the output
queues. The DSCP mapping method is applied per device, although it may
be enabled or disabled on individual ports. Non-IP packets are classified as
Best Effort.
Advanced QoS Mode
In Advanced QoS mode, administrators define forwarding rules which specify
flow classifications, and set bandwidth management and queueing assignments
to these flows.
After assigning packets to a specific queue, services such as configuring output
queues for the scheduling scheme, or CIR, per interface can be applied. Note that
packets may egress with a different VPT tag than that with which they ingressed.
When using trust VPT this caveat does not exist, and packets egress with the
same VPT with which they ingressed.
In Advanced QoS mode, administrators set up policies and assign them to
interfaces. Policies are composed of several user-defined configurations, such as:
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Out of Profile DSCP Assignments — Assigning the outgoing DSCP tags that
takes the place of the incoming DSCP tags.
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Policy Name — Creating new policies which can be assigned to interfaces.
Policies can be composed of an ACL and QoS rules.
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Class Map — Defining class maps, consisting of one IP ACL and/or one
MAC ACL.
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Aggregate Policer — Applying aggregate policers to multiple classes in the
same policy map.
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Interface To Policy — Binding QoS policies to interfaces.
— In this mode, users can assign a default queue for
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