[c-nsp] Burst Size Parameter

[Saku Ytti]

On (2013-06-17 11:24 -0700), Dhamija Amit wrote:

> I was going through burst size calculation for police command , and i found at most of links where recommendation is to use the bc values as 1.5sec * CIR/8 and Be as twice the bc. 

> Also i saw some of juniper documentation which says or define the burst size in bytes and expressed in 10ms or 25 ms and which in turn never allowed to burst the customer more then his CIR if it's more then CIR then it goes into exceed action catagory.

It's always above CIR when it's bursting. 

Issue here is, your ingress rate is faster than egress rate, if you don't
allow any bursting, then each packet exceeds the CIR, and effective rate is
0.

I find JNPR documents sensible, where CIR burst is dimensioned based on the
interface physical rate. Then you multiply that rate with how long bursts
you want to handle.

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  ++ytti