QoS-IP Precedence

[forsudhaji]

Hi,

I have a query as regds QoS. Say am an ISP and am prioritising voice traffic in my network by setting an IP Precedence value for voice traffic say X.

I have many customers connected to my network. One of my customer wants to prioritise his Voice/SAP traffic compared to his normal data traffic.

But he hasn't informed the ISP nor signed any SLA for that. He manages his CPE and he sets the same IP Precedence value X for his SAP/Voice traffic and sends it to my network.

In this Scenario..my network unknowingly carries one of my customer's SAP traffic with high priority..Right?

How do I override this? Pls let me know..If possible with some configs..

Thanx

Sudha.

[barisal]

Yes you are right. You carry the customer's SAP traffic in strictly priotised class. However, you may change the IP Precedence value at the point where this customer is terminated at your backbone router and then this traffic will flow with its new precedence through your network. Just put a input PBR related config under the related interface. For achieving this, you hould know the related SAP ports, i say ports, you may not know from which IP addresses your customer sends SAP traffic. Even if you know, they may change it.

int bla bla...

ip policy route-map SAP

!

Remember taht PBR allows works in "in-direction"

access-list 100 permit bla bla... (to catch the SAP traffic)

route-map SAP permit 10

macth ip address 100

set ip precedence routine (zero for example)

!

route-map permit 20

!

I hope this helps...

Regards,

[forsudhaji]

Hi,

Thanx for ur reply. Assume am a big ISP and I have some 500 cusctomers. Do u want me to apply this Route map on all 500 interfaces??Is there any possible way of simplifying this task?Pls let me know..

Regards.

[barisal]

Hi;

It depends on your customers' behaviours. If all of your customers are suspicious for you, you should make this configuration. By the way, it is essential to take the routers' CPU and memory acts into consideration because such a conf. will raise the CPU usage. However, it is a common behaviour that you may only put this conf. under the core links not on the ones every customers are ended. So customer will only consume his links. But on the core links, the precedence will be set to zero for the related traffic only, it is very important that you shuld not set real precedence 5 critical traffic not to set to something else. So, it may rescue your reserved bandwith, maybe in the core backbone lines.

Regards,