[c-nsp] 6500 service-policy

[Clinton Work]

I have seen tech notes by Cisco that if you want the policer to be friendly 
to TCP traffic you should allow up to 1 second of burst at the committed rate.

mls qos aggregate-policer 25000000 3125000

I find this a little excessive and I tend to use 1/5 second as my guideline:
mls qos aggregate-policer 25000000 625000

It all depends upon how much burst or back to back Ethernet frames you want
to allow.

Other notes:
  - Policer will count the L2 Ethernet header (exluding the 4-byte CRC)
  - To sustain a specific rate, set the token bucket size to be at least the 
rate value divided by 4000, because tokens are removed from the bucket every 
1/4000th of a second (0.25 ms).  This mean the minimum support Bc is 4000.
   In your case 25000000 / 8 / 4000 == 782 which is less than the minimum.


Jean-Christophe Varaillon wrote:
> Hi,
> 
> I want to limit the use of bandwidth on an copper GigabitEthernet
> switched port (6500 - native - msfc3):
> 
> mls qos aggregate-policer Max25Mbps <CIR> <Bc> <Be>
> 
> I have a well know CIR, but I need to adjust the Bc (I don't touch the
> Be).
> 
> Could I have a CIR = Bc or it's better practice to have a Tc<1 ?
> 

-- 
===================================================
Clinton Work	clinton at scripty.com
Calgary, AB