How to setup QOS on WAN inbound interface

[ciscoroyzhang]

HI all

I have found a lot of discussion on how to setup QOS/auto QOS on the router for outbound traffic, but no many for inbound traffic. does it required if yes how to setup them up? 

Let's say we have QOS SLA with WAN carrier and voice packet with dscp marketing ef  is forward to our CE router interface fa0/1.

On the CE router I will create following policy-map:

)# policy-map          VOIP-QOS-POLICY-IN

)# class VOIP-RTP

)#priority 90

)# class VOIP-CONTROL

)# bandwidth 30

)# class class-default

)# fair-queue

)# int fa0/1

)# service-policy input VOIP-QOS-POLICY-IN

Basically I want to prioritize the RTP stream when it reach to CE Wan interface and does above approach meet my goal?

Thanks in advance  Roy

[Chris Deren]

You do not apply and policy on the ingress side, only egress side to WAN. The only reason you would want to apply somethign on ingress side is if you need to remark any packets.

HTH,

Chris

[paolo bevilacqua]

Furthermore to Chris comment, sInce your CE interface is a LAN, it will never experience congestion, so there is no need to apply any QoS on it.

[ciscoroyzhang]

HI guys

the interface fa0/1 is just example, we used ATM, E1 and FR etc. here I just try to simplify sinario.

OK, back to Chris comment, if there is no need to prioritize on the ingress buffer, how router know to treat the RTP stream differently from other default class traffic? 

[Chris Deren]

It doesn't, it's FIFO and you cannot control how the packets arrive to you, that's the PE router's job.

Chris