From: Jonas.Dormagen@xxxxxxxx
Date: Tue Jun 06 2000 - 09:18:05 GMT-3
Hello all,
SORRY for the wrong calculation.
Look at the following..once more.
It is :q1=70%, q2=20% , q3=10 % of the linkspeed.
If the link has e.g. CIR=32kbps EIR=16kbps so AIR=48000
So for each cycle we have to send :
Assumption the packet is 1500 bytes big.
q1 : 48000 * 70% = 33600 bits = 4200 byte -> and i you want to have 7 here us
e
10500 bytes.
q2 : 48000 * 20% = 9600 bits = 1200 byte -> if you have two packets here use
3000 bytes.
q3 : 48000 * 10% = 4800 bits = 600 byte -> to have one packet here increase
the value to 1480 bytes.
Now we have all in all 10500 bytes + 3000 bytes + 1480 bytes = 14980 bytes.
Means it will take 2.5 seconds to emty all FULL queues. What is acceptable.
You have to calculate the byte-values from the smallest queue up to the bigest
queue.
best regareds
Jonas
---------------------- Forwarded by Jonas Dormagen/Frankfurt/SITA/WW on
06/06/2000 12:58 PM ---------------------------
Please respond to Jonas.Dormagen@sita.int
To: "Earl Aboytes" <Earl@Linkline.Com>
cc: Ccielab@Groupstudy.Com (Bcc: Jonas Dormagen)
Subject: Re: custom queueing
Hi Earl,
I have some experiences with the "nightmare" of COQ. The key issue is the AIR
of the uses link.
I am using the following configuration in a very large VPN.
It is :q1=70%, q2=20% , q3=10 % of the linkspeed.
If the link has e.g. CIR=32kbps EIR=16kbps so AIR=48000
So for each cycle we have to send :
q1 : 48000 * 70% = 33600
q2 : 48000* 20% = 9600
q3 : 48000*10% = 4800 (this represent 4 packets of 1500 bytes)
to fill the AIR in 1s.
We can decide to use these values as byte count for each queue.
Or to be smooth we can decide to complete a cycle in less than 1s.
So for example to send 2 packets in q3 instead of 4 .
To be sure not to send more than 2 packets (2*1500=3000) let use q3 byte-count
=
2990
So q2 byte-count should be the double of q3 byte count => 6000
and q1 byte-count should be q3 byte-count * 7 > 21000.
The idea is to be smooth to avoid traffic to be bursted / to wait on each queue
even on small links.
Is you are smooth on small link, then you will be smooth on big link, so there
is no need the change
the values with bigger AIR.
I hope this help.
best regards
Jonas
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