Cisco's explanation of custom queueing is about as clear as the mud in my
front yard right now. I'll try to simplify this is a way that makes sense.
With CQ, you define different types of traffic and then assign them a
certain byte count based on how much weight you want to give that traffic.
The total byte count of all queues is somewhat arbitrary in many cases, but
your choices can have unforseen results.
Let's use an example and it will be more clear. Let's say you have three
types of traffic: One that is *really* important, another that is almost as
important, and then a bunch of other traffic that isn't as important. You
arbitrarily decide that you want the highest priority traffic to get 50% of
the bandwidth. The next higher priority traffic gets 25%. The rest of the
traffic gets a measly 25% during periods of congestion.
Now you need to know some basic math. :-) We have to convert these
percentages to some sort of byte count. If you want to base this on a total
byte count of 10,000 bytes, your figures look like this:
First queue: 50% of 10,000 = 5,000
Second queue: 25% of 10,000 = 2,500
Default queue: 25% of 10,000 = 2,500
This will roughly ( and I mean *roughly*) get you the percentages you
desire, but this is greatly affected by the frame size. In CQ, a queue
doesn't break up a frame and will queue up an entire frame before moving on
to the next queue.
For example, if you already have 4,800 bytes in the first queue and another
1500 byte frame comes in for that queue, all 1500 bytes will go into the
queue before the queue is emptied. This can seriously mess up your
percentages so take that into consideration.
If you're using smaller frames it might be a good idea to use a smaller
total byte count. For instance, if you're doing a lot of VoIP and for some
strange reason decide to use CQ (LLQ is better) then you'd definitely want
to use smaller queue sizes to avoid jitter and delay.
For traffic not senstive to minor latency or one high speed links you can
feel safer using larger queue sizes.
Does that help? If not, please let me know and I'll try to be more clear.
And if I've made any mistakes, someone please correct me. It's past my
bedtime and I'm dozing off. :-)
Regards,
John
| Hi Friends,
|
| Can any one here please explain what should be the"bandwidth Value" if we
| need to divide traffic by percentage ,using Custom queuing.
|
| As far as I know(IF Im right )during our lab,as we usually take clock as
| 64Kbps,then we need to divide this factor (64/8) among the traffic.
|
| What about others????I m still confused..
|
| Hey!!!!!!!!Can you please solve my confusion.,.....(examples preffered :)
|
|
| Thanks.
|
| _________________________________________________________________
| Get your FREE download of MSN Explorer at
http://explorer.msn.com/intl.asp
|
|
|
|
_______________________________________________________
Send a cool gift with your E-Card
http://www.bluemountain.com/giftcenter/
Message Posted at:
http://www.groupstudy.com/form/read.php?f=7&i=17625&t=17622
--------------------------------------------------
FAQ, list archives, and subscription info: http://www.groupstudy.com/list/cisco.html
Report misconduct and Nondisclosure violations to [EMAIL PROTECTED]
