I have a big question with these kind of exercises, the Majority of questions 
that I have seen (INE,IPexpert and Yusuf) they mostlikely want you to restrict 
the traffic to a certain value, but in very few cases they ask you to configure 
the BC TC and the other values. 

I guess my question is, if not specified, what should we do, we leave it as it 
is? Or do we apply the values that appear on the doc? Cuz I would expect that 
the question would say something like, "use the values recommended" or 
something about the values... 


Mike 



Date: Mon, 23 Apr 2012 22:01:02 +0530
From: [email protected]
To: [email protected]
CC: [email protected]
Subject: Re: [OSL | CCIE_Security] Formula to calculate Burst value

Tc is involved in both shaping and policing.

With policing, Tc is the seconds for which tokens are put in the bucket.

With regards
Kings

On Mon, Apr 23, 2012 at 7:26 PM, Joe Astorino <[email protected]> wrote:

The forumulas for calculating the Bc and Be for policing are how you have 
defined, them but I would be careful with the use of the term "Tc" when dealing 
with policing.  Tc is generally a term that applies to traffic shaping and not 
traffic policing.  Why?  What does Tc do for us?  With a shaper, Tc is a static 
defined interval of time.  As you know, each Tc interval we get to add Bc 
tokens to the bucket to use.  Traffic policing does not work the same way, 
contrary to popular belief. With traffic policing, the token bucket is 
refreshed based on a function of 2 things: The CIR value and the amount of time 
passed since the last packet was received.  It has nothing to do with Tc.  



My point is simply that Tc is not involved with the calculations of traffic 
policing, as it is a concept that applies to traffic shaping.

On Sun, Apr 22, 2012 at 12:32 PM, Kingsley Charles <[email protected]> 
wrote:


Hi all

The following is how we calculate Bc for QoS MQC policing and TCP 
rate-limiting. Now for ZPF policing, which formula should be used. I need Cisco 
doc for confirmation.




Policing
========

Tc = 0.25 secs


BC = CIR/8 * 0.25 = CIR/32

Be = Bc, if not specified


TCP Rate-limiting
=============

Tc = 1.5 secs

BC = CIR/8 * 1.5

BE = 2 BC


With regards
Kings


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-- 
Regards,



Joe Astorino

CCIE #24347

http://astorinonetworks.com

"He not busy being born is busy dying" - Dylan






_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Are you a CCNP or CCIE and looking for a job? Check out 
www.PlatinumPlacement.com                                         
_______________________________________________
For more information regarding industry leading CCIE Lab training, please visit 
www.ipexpert.com

Are you a CCNP or CCIE and looking for a job? Check out 
www.PlatinumPlacement.com

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