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So where would you use polices and where would you use shapers.

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Polices are generally used as ingress tools.

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In other words the traffic has dropped before it's processed so that you don't waste valuable resources.

4
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If a package is going to be dropped anyway you might as well drop it on the ingress or incoming interface

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of a rider so that you don't waste valuable bandwidth and you cycles to move it from one interface to

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another to a running lookup and so forth and then drop the packet.

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Polices can be used on aggress to control the amount of traffic sent out of an interface but are generally

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used to enforce a traffic policy on ingress as an example your service provider may have an ingress

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police to ensure that you don't send too much traffic as an example you could have paid for 100 megabits

10
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per second.

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Internet link but the physical interface that connects you to your service provider could be Gigabit

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Ethernet so to ensure that you don't transmit more than 100 megabits per second the service provider

13
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on the ingress interface on the ISP side will implement a police to drop traffic that exceeds 100 megabits

14
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per second when traffic is exceeded.

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The police can either drop the traffic or remake the traffic.

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The disadvantage of a police is that stopping traffic which results in TTP resets TTP is designed to

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re transmit traffic that's been dropped.

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So when a police is dropping a lot of traffic it causes a lot of TTP re transmissions or re sends polices

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don't introduce chatter or delay because they simply drop the packet.

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They don't delay it with shapers introduced delay and Jetta by slowing down packets or buffering them

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for a period of time before transmitting them.

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Shapers are a lot gentler than polices so generally they are deployed between an enterprise customer

23
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and the service provider to ensure that you don't exceed the contracted rate again using the example

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of a customer connected to a service provider via a gigabit interface.

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The customer will slow itself down under the 100 megabits per second threshold to ensure that it doesn't

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send traffic to the service provider who will simply drop the traffic shapers result in fewer TCB re

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transmissions because they're not dropping the traffic they are delaying it or slowing the traffic down.

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So in summary policing drops or remarks it doesn't buffer it causes TTP read transmissions it doesn't

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introduce G2 and delay shapers don't drop traffic they delay the traffic but that can result in additional

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delay or jitter shaping is a lot gentler on traffic.

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Policing is very harsh causes re transmissions.