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QoS applied to input on an interface

0rsnaric
Level 1
Level 1

What is the best method for guaranteeing bandwidth to an internal host through a router?  I would like to use the internet facing interface and apply an input service-policy map.  However, it looks like I can't do that, as I get "...not supported in input policy."

Basically I want to use a policy-map to set a guaranteed min. bandwidth of 20000 to a host defined in a class-map, and then apply that service-policy to an interface's input.

There a better way?

Doesn't make sense to do it on the inside interface as an output.

Thanks.

10 Replies 10

nkarpysh
Cisco Employee
Cisco Employee

Hello,

What is the platform/IOS you are referring to?

Niko

HTH,
Niko

amabdelh
Level 1
Level 1

Hi
First, can you show us what was your policy-map and the class-maps? This will help us find why it is not. Supported
Second, the best way depends on why do you need it, if you need to give more download rate to this host then i think you need your ISP apply the policy-map on his router, because applying on on your router will be useless as the router is at your end of the circuit
But if you need to give more upload bandwidth to this host, then you can either put it in the ingress port or the egress with inbound or outbound direction

Sent from Cisco Technical Support iPhone App

This is a 2921 router running IOS 15.1(2)T1.

Here are the commands -

access-list 101 permit ip any X.X.X.8 any

class-map CENTRAL

                match access-group name CENTRAL

policy-map web_conferencing

                class CENTRAL

                                bandwidth 20000

                class class-default

                                fair-queue

interface gig0/0

                service-policy input web_conferencing

Can you try to remove "fair-queue" from the class-default?

in code 15.X, WFQ are no longer supported, please check and let me know if that works.

Thanks

This is how it looks now -

class-map match-all CENTRAL

match access-group name CENTRAL

!

!

policy-map web_conferencing

class CENTRAL

    bandwidth 20000

And this is what happens when I try to apply it-

(config-if)#service-policy input web_conferencing

Weighted Fair Queueing feature not supported in input policy.

Bandwidth command not allowed at parent level in input direction

Have you able to fix this ? . I'm also having same issue 

platform is 881 with c880data-universalk9-mz.154-3.M4.bin

Ingress policies, for bandwidth management, generally only support policing.

You can somewhat "guarantee" bandwidth for some ingress traffic by policing other traffic to "reserve" bandwidth for it. For example, if you had 1 Mbps ingress, if you policed all traffic but "X" to 500 Kbps, in theory, you've "reserved" 500 Kbps for "X" traffic.

In practice, though, since the policer in downstream, it doesn't preclude non-"X" traffic using more than the policed value. However, some flow rate adaptive traffic, e.g. TCP, will slow itself when it "sees" drops (due to policing). I.e. for such traffic, policing will have some impact, but it's imprecise.

and forgot to mention, queing only done on egress

if you want to use it on ingress direction, then you have to use policing, it will help you but this will be more complicated

Okay, I'll take a look at policing.  Thanks Amjad!

QOS has the following sequance of operations:

Classify-Mark-Bandwidth and priority.

Classify is a load on the processor and better to be done while the packet input to the network.

So, it is applied on input interface. It could be applied on output also to deal with different WAN technology (ATM & MPLS for example).

And hence it mark the packet

Bandwidth and Priority by logic is to be done on the output interface.

The router may has more than one interface with different speeds

Hence, each class will have different bandwidth on each interface.

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