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Once traffic is identified it can be treated in a number of different ways.

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You could as an example give it a minimum amount of bandwidth.

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You could give it a maximum amount of bandwidth or a limit on the amount of bandwidth that it can send

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some queuing mechanisms provide a minimum bandwidth guarantee policing and shaping the limit the amount

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of traffic that you can transmit.

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So polices and shapers are both great limiters but they differ in how they treat excess traffic as a

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general rule of thumb.

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Polices will drop excess traffic with traffic shapers will delay excess traffic.

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In this example we've got traffic sent at different rates and administrator has configured a maximum

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limit.

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However as shown by this line here with policing any excess traffic is automatically dropped.

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So polices will perform checks for traffic violations against a configured rate set by an administrator

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which could be you to action that a police takes in response to traffic would either be dropping the

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traffic as shown here or it could remark excess traffic and still transmit the traffic.

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There are different options you could just transmit the traffic as long as you are below the threshold.

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You could configure a police search or send the traffic without any modification as long as it's below

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the configured threshold when it goes above the configured threshold.

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You could read market but still transmit it and that would be true for traffic between the threshold

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and a second threshold but any traffic exceeding the second threshold would be dropped.

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We have this concept of a tri color or three color implementation when traffic is below the first threshold

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it's transmitted as normal when it exceeds the first threshold but it's below a second threshold.

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It will be remarked to our lower class.

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So in other words you are moved from first class to economy as an example but to the traffic is still

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transmitted.

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And when you go above the second threshold you are simply kicked off the plane or in a data network.

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The traffic has dropped.

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What's important to understand about polices is that they do not delay traffic.

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They will check the traffic and either remarketing and transmit it or drop it.

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They do not buffer or delay traffic shapers on the other hand will delay traffic.

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So they try and smooth traffic out by buffering it.

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So if we look at our original traffic when it's shaped notice the curve.

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Here is a lot smoother as the traffic is delayed so that it falls within a configured bitrate so the

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shape doesn't drop the traffic but smooth it out by delaying the traffic to make sure that over a period

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of time the traffic falls within a configured bitrate shape as are usually used to meet service level

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agreements when the traffic spikes above the contracted rate.

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The excess traffic is buffered and is delayed until it falls below the contracted rate.

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Polices are a lot harsher.

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They will drop as effective way as a shaper will try and smooth the traffic out over a period of time

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to get it below a configured rate.