NAT overloading with QoS

[stella.florence]

Hi,

I've already configured NAT overloading(PAT) in a 1841 router.Now i want to configure QoS to prioritize voice traffic. How can i classify the traffic ,b'coz the port numbers are translated by PAT configuration.Can i use NBAR to classify the dynamic ports.

Thanks and Regards,

Stella Florence W.

[spremkumar]

Hi

Are you trying to configure qos on the link connected to internet ?

To have desired results with qos you need to have end to end config similarity in addition to the path devices to have same kinda config.

Without which the qos config you do at your end wont be effective.

regds

[jbrunner007]

i assume you just want to do queueing for the outbound (egress) data to the internet, from your router?

You can make an inbound service policy (on the lan f0/0 interface) which marks the packets with ip dscp before they are natted. Your packet markings should still be relevant (remaining marked) once they get to the other side of the router... This side is where you have your outbound service policy, which is actually doing the queueing...

So, mark on the lan inbound, and queue on the way out... so why not do something like this...

class-map match-any voicemark

match protocol rtp audio

class-map match-any voicesignalmark

match protocol h323

match protocol rtcp

policy-map inboundmark

class voicemark

set ip dscp ef

class voicesignalmark

set ip dscp cs3

int f0/0

service-policy input inboundmark

class voice

match ip dscp ef

class voicesignal

match ip dscp cs3

policy-map outboundqueue

class voice

match ip dscp ef

priority percent 25

class voicesignal

match ip dscp cs3

bandwidth percent 10

class class-default

fair-queue

int s0/0

service-policy output outboundqueue

[stella.florence]

Hi,

Thanks for your reply. I thought of doing similar thing. Your reply confirms it.

Thanks and Regards,

Stella Florence