Quality of Service (QoS): Managing Bandwidth More Effectively
Preparation for Configuring QoS
TableQoS Options for Prioritizing Outbound Traffic | QoS Types | ||
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| Source- | |
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| Precedence | Port |
Option 1: | Prioritize traffic by sending specific packet | Yes 1 | Yes |
Configure 802.1p | types (determined by QoS type) to different |
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Priority Rules | outbound port queues on the switch. |
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Only | Rely on |
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| priority as an 802.1p value to downstream |
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| devices. |
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Option 2: Configure ToS DSCP Policies with 802.1p Priorities
Prioritize traffic by sending specific packet | No | Yes |
types (determined by QoS type) to different |
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outbound port queues on the switch. |
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Propagate a service policy by reconfiguring |
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the DSCP in outbound IP packets according |
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to packet type. The packet is placed in an |
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outbound port queue according to the 802.1p |
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priority configured for that DSCP policy. (The |
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policy assumes that downstream devices can |
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be configured to recognize the DSCP in IP |
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packets and implement the service policy it |
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indicates.) |
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Use |
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priority as an 802.1p value to downstream |
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devices. |
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1In this mode the configuration is fixed. You cannot change the automatic priority assignment when using
3.If you want to include 802.1p priority settings in outbound packets, ensure that tagged VLANs are configured on the appropriate downstream links.
4.Determine the actual QoS configuration changes you will need to make on each
5.Before configuring QoS on a switch, refer to the next section, “Planning a QoS Configuration” for information on