Load due to PBR

[gaurav.prakash]

Hi I have 1721 with DSL service on it..I have around 4 atm sub interfaces.. I need to have PBR to change the next hop for all traffic comming from different interfaces excpet one..

Do I need to change the router to 2600, will it consume too much cpe..I have 12.3 IOS on 1721..

Any comment..

regards,

G

[lgijssel]

Yes, PBR is extremely heavy on the CPU. Depending on the CPU, PBR will not be able to process more than 1.000 - 10.000 pps. On the 1721 I estimate no more than 2.000 pps before the CPU hits the ceiling.

You should perhaps use a 2800 series instead, and then the 2821 at least if you want to get some decent performance with this setup.

In newer IOS's there is the command: ip route-cache policy. This should speed things up considerably but I have a TAC case opened myself at this moment because this command is appearently not working.

Regards,

Leo

[gaurav.prakash]

Thx Leo,

Ref :

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Do you mean 2 packets per seconds here? I can see ip route-cache policy in ios..

Regards,

Gaurav

[lgijssel]

No, I'm sorry. It's the american notation with dots at thousands. So I meant 2000 packets per second.

Regards,

Leo

[jackyoung]

Agreed w/Leo. The loading of the PBR depends on the no. of packet pass through the PBR enabled interface, if the interface loading is highm then PBR loading will high. The reason is the PBR will examine each packet to determine if it matchs the policy map.

Therefore, if the ADSL interface w/ low bandwidth, it MAY work, otherwise, you will hit the performance issue. You can try to check the no. of packet in the ATM interface to determine the upgrade requirement.

Hope this helps.

[m-haddad]

You should be fine with the 1700. Make sure you enable fast switch CEF.

If the bandwidth is high you will need to upgrade to higher router model such as 2800 because 2600 routers are discontinued,

Regards,

[gauravprakash]

Thx,

Any guess after how much BW of traffic 2M/ or 4M should I upgrade..

Regards,

Gaurav

[jackyoung]

Nobody other than the user will know their requirement. You should forecast the traffic loading in future and consider the new bandwidth upgrade volume and schedule. You also need to consider the leadtime to order the equipment + the new line ready for use.

And the new BW requirement will also lead to new hardware requirement or connection media change.

[m-haddad]

Hello,

2MB on 1700 with basic routing should be fine. If you are going to do QoS or VPN I recommend upgrading to 2811. Therefore, 2Mb with basic routing and PBR you should be fine.

Please rate if I could help,

Thanks,