Traffic Shaping - Policing Question

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Jun 23rd, 2009
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I've never been able to get this to work right and am going to make another attempt. I have a multimeg frame relay circuit with 3 megabits total bandwidth. I want restrict outbound to 2.5 Mbps. Not sure how to accomplish this.

So far, from what I've read, it would look something like this but I'm not sure which interface to apply it to. It's 2 serials combined with a subinterface (MFR1.500) so where to apply it?

map-class frame-relay 1Mbps

frame-relay cir 1000000

interface ?????

frame traffic-shaping

frame interface-dlci xxx

class 2.5Mbps


policy-map 2.5Mbps

class class-default

police cir 2500000

map-class frame-relay 2.5Mbps

service-policy output 2.5Mbps

Any help would be greatly appreciated

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francisco_1 Tue, 06/23/2009 - 06:51
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you could shaping instead. see example below...

Policy-map FR

class class-default

shape average [either use percentage or bits per sec - enter your bandwidth here]

map-class frame-relay Test

service-policy output FR

int serial1/0

frame-relay traffic shaping

frame-relay class Test

pls note the class Test will affect all VC's under the interface.

dj214 Tue, 06/23/2009 - 07:05
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Thanks - just need a little clarification on 2 points. I have 2 serials, so I need to shape on both correct?

2nd question - with regards to using percentage vs using bits how is that written 75% for example?

Thanks again

francisco_1 Tue, 06/23/2009 - 07:17
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best to do it on the hub if you have hub&spoke. if you want to shape 75% of the reserved bandwidth, the use 75%. I believe by default 75% of the interface bandwidth is reseved by the "max-reserved-bandwidth" command.

dj214 Tue, 06/23/2009 - 08:57
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thanks - when I try to apply it to the interface I get

interface bandwidth is less than 8000 bps.

Very aggravating. What can I be doing wrong?

dj214 Tue, 06/23/2009 - 10:03
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What I wound up doing and it seems to be working fine is on each serial in the bundle:

traffic-shape rate

Looks to be working good, any downside to doing it this way?

francisco_1 Wed, 06/24/2009 - 00:33
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by just applying generic shaping directly under the interface will work but it's not scalable. In your case you better off using MQC frame-relay traffic shaping using the map-class and referencing a policy-map. By doing it this way you can apply shaping per DLCI's because by default when you apply it under the serial interface, the shaping affects all DLCI's configure under the interface.

see this

if error you are getting, send me the output show run int [your frame-relay interface]

sh int [frame-relay interface]

dj214 Wed, 06/24/2009 - 04:32
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Thanks - I tried again using map-class and found my mistake was applying it to the wrong interface (sub interface).

This works perfectly at limiting bandwidth but I'm still confronted with the orginal problem that brought me here to trying to limit outbound bandwidth.

This circuit is a multimeg (3meg total). There is so much congestion outbound, that connection to a web server running on this circuit are very slow and often timeout. When I applied the policy map, I effectively cut outbound traffic to 2.5 Mbits but still the connections to web server from the outside are terrible.

I looked at the interface that I applied policy map to and see alot of drops, which I assume is because of the policy map itlself but I also assume that it's responsible for connections issues to web server.

Any thoughts on this?

Thanks again for all of your input, it's been very helpful.

Joseph W. Doherty Wed, 06/24/2009 - 06:18
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Other than many shaper's implementation of (W)FQ, if you have outbound congestion, you might be better served but how you manage that congestion.

Could you clarify what type of multi-meg interface this is that provides 3 Mbps? I would assume it's something like dual T-1s, but if so, they're not bonded?


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