RE: Formulas for calculating QOS Values

From: James Matrisciano (jmatrisciano@kenttech.com)
Date: Mon May 09 2005 - 08:54:34 GMT-3


For traffic shapping, you want to use Cir, Be, Bc and Te

If you know any of the above mentioned, you can figure out the rest with
this...

CIR X Tc / 1000 = Bc
CIR / Bc x 1000 = Tc
CIR - AR x Tc / 1000 = Be
Bc x 1000 / Tc = Cir

On Custom Ques, you need to know how to get the percentages for traffic
to byte counts...

So,
If you need to allocate 30% of BW for WWW traffic with a packet size of
1500 bytes

As well Allocate 20% of BW for ftp traffic with a packet size of
600...do the following

Step 1. Find which has the largest packet size....(1500 for www)

Step 2. Divide all other traffic fields by the largest packet size

1500/1500=1
1500/600=2.5

Step 3. Multiply the #'s that were given by division by the BW
percentage

(in step 2 1500/1500=1) so 1 x 30% (1x .3) = .3
(in step two 600/1500=2.5) so 2.5 x .2 (20%) = .5

Step 4. Take that number, normalize it and round up if needed:

.3 normalized is 3
.5 nrmalized is 5

(for something like .75, normalized is 7.5, you then need to round up to
8)

Step 5. Multiply the normalized number times the original byte count.

3x1500=4500
5x600=3000

Now you can build your custom ques:

Queue-list 1 port ip 1 tcp www
Queue-list 1 port ip 2 tcp ftp
Queue-list 1 port ip 2 tcp ftp-data

Queue-list 1 que 1 byte-count 4500
Queue-list 1 que 2 byte-count 3000

Then apply where applicable

Netmasters has a great write up on this in lab 1 I believe.

jm

-----Original Message-----
From: nobody@groupstudy.com [mailto:nobody@groupstudy.com] On Behalf Of
aji nc
Sent: Monday, May 09, 2005 3:14 AM
To: ccielab@groupstudy.com
Subject: Formulas for calculating QOS Values

Dear all,

   Can anybody summarize the formulas for calculating
different QOS values. I am getting lost by seeing
different values at different places.I am looking for
ccie lab recomendations.

Ratelimit:
normal burst = configured rate * (1 byte)/(8 bits) *
1.5 seconds

extended burst = 2 * normal burst

police in MQC : ? is it the same or something
different

FRTS : inside map-class

bc = cir*125/1000 for data
     cir*10/1000 for voice

be = (ar-cir)*125/1000 data
be for voice is 0

mincir = cir/2 for data
mincir = cir for voice

frame-relay traffic-rate command : i am lost ?

MQC based frts:

 shape command : is the values are same as above or
something diferent ?

Generic traffic shaping : fraffic-shape rate

i am lost!!! can anybody help me ?

where do u use gts and where frts ?

Thanks in advance

Aji.N.C

 
     

                
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