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Burst Time Calculation

Posted: Tue Apr 09, 2013 5:15 pm
by rabeulbd
Hi,

I have confused in Queue for setting burst limit, burst threshold etc.
My question is below..
1. How to calculate burst time?
2. How to calculate burst threshold?
3. How to calculate burst limit ?
4. How to calculate max-limit ?

please answer my question in step by step.

Thanks
Rabeul Islam

Re: Burst Time Calculation

Posted: Sat Apr 20, 2013 4:32 am
by joshaven
Burst time is the time that you want the router to track over.

You could set the burst for 2 times your bandwidth target for a time of 5 seconds. This would mean that it will burst until the average over the last 5 seconds reached twice your limit. The max limit is the max that you want to provide not counting burst. For example. 3m would be three megabits per second.

Re: Burst Time Calculation

Posted: Tue Apr 23, 2013 10:01 pm
by kraker
hi joshaven,

could you please explain this issue with the example..

thanks....

Re: Burst Time Calculation

Posted: Tue Apr 23, 2013 11:34 pm
by joshaven
Hopefully this will help

Re: Burst Time Calculation

Posted: Wed Apr 24, 2013 9:45 am
by kraker
thanks your answer..It's really helpful..But how many times in a day it will use burst.Can we limit this queue during the day usage..

ex: 5 times use burst limit in a day ...

thanks....

Re: Burst Time Calculation

Posted: Wed Apr 24, 2013 2:17 pm
by joshaven
It doesn't work on times per day. It's more like it recharges. When a user doesn't use the traffic at all the 10 second average goes to 0 so the next time traffic is requested then it will be at the burst speed. If the burst time is extended to longer like an hour then its averaging over an hour and the user will be close to always on burst.

What are you trying to accomplish?

Re: Burst Time Calculation

Posted: Wed Apr 24, 2013 4:03 pm
by kraker
we want to offer to our customer new dsl package..like;

Until 8mbit speed ---(speedtest.net shows it around 4-8mbit accord. burst time) without burst 1,2 mbit.

Until 16mbit speed ---(speedtest.net shows it around 10-16 mbit accord. burst time) without burst 2,4 mbit.

this is our speed strategy at dsl side.other dsl providers doing this.

can u suggest any idea about this issue ?

thanks...

Re: Burst Time Calculation

Posted: Wed Apr 24, 2013 5:27 pm
by joshaven
I am a bit unclear of your need so I want to restate it in my words to see if I understand.

One speed plan 8Mbps Maximum Throughput, 1200Kbps sustained traffic.
A second speed plan of 16Mbps Maximum Throughput, 2400Kbps sustained traffic.

If this is correct then the speed plan is not complicated, although the burst is quite a bit higher then the sustained speed. A large burst isn't a problem technically, it's more of a business decision.

One more question is do you want to maintain the highest speed for the customer that you can or just cut it down to share equally? You may be looking for a simple committed information rate (CIR = limit-at) and maximum information rate (MIR = max-limit) solution rather then a burst solution or a combination of the two.

Re: Burst Time Calculation

Posted: Thu Apr 25, 2013 10:40 am
by kraker
hi,

this speed's (8 mb,16mb) showing to customer only they want to check speedtest via speedtest.net web page or another one.normally they used 1200kbps or 2400kbps sustained.

we don't want to maintain higher speed to customer , all dsl user's will be use same internet pool but we should save their sustained speed.

***You may be looking for a simple committed information rate (CIR = limit-at) and maximum information rate (MIR = max-limit) solution rather then a burst solution or a combination of the two.***

ı don't have an idea about this features.but cır is may be possible to use..

really thanks for your help...

Re: Burst Time Calculation

Posted: Fri Apr 26, 2013 3:15 pm
by deejayq
i think he's trying to achieve what Comcast is doing with PowerBoost

Re: Burst Time Calculation

Posted: Fri Apr 26, 2013 4:03 pm
by joshaven
i think he's trying to achieve what Comcast is doing with PowerBoost
I looked up PowerBoost
What is PowerBoost?
PowerBoost is a patent-pending Comcast network technology that enables you to experience faster connection speeds while you are downloading and uploading large files to the Internet. PowerBoost leverages an additional capacity that is already built into Comcast's advanced network.

How long does the PowerBoost burst last?
PowerBoost provides bursts for the first 20 MB downloading and the first 10 MB uploading of a file respectively on select Comcast High-Speed Internet services.
My first though is then to mark connections once they have exceeded 1mbit with a connection mark to identify 'large downloads' then mark all packets with that connection mark. Then have a PCQ "boost" queue that can be matched for those packets. Any connections that exceed 160Mbit (20MByte) should then have the connection mark removed. (This is a rough off the top of my head way of following these guidelines if that is what is wanted.)

Re: Burst Time Calculation

Posted: Fri Apr 26, 2013 4:22 pm
by joshaven
hi,
this speed's (8 mb,16mb) showing to customer only they want to check speedtest via speedtest.net web page or another one.normally they used 1200kbps or 2400kbps sustained.

we don't want to maintain higher speed to customer , all dsl user's will be use same internet pool but we should save their sustained speed.
You could probably use a layer7 match to set speedtest.net connections to a higher speed if that is what your trying to accomplish. I would guess that your not really wanting to do that though.

I would supposed that your trying to conserve bandwidth yet give the experience of high speed.

This can be done through identifying traffic types and working with these types. Burst web traffic. Don't burst streaming traffic like netflix. Netflix in particular doesn't work well with a burst, when it initializes with a burst it wants to maintain that speed for the entire video. Its better to begin and maintain a Netflix connection at 2Mbps then to begin at 10Mbsp and slow down to 2Mbps. However if you load a web page at 10Mbps it could be all loaded in the burst and the user will feel snappy speed.

If you want to do this well then check these guys out: http://www.proceranetworks.com/ but you may have to take out a loan to do it. If you want to be cheap and get close enough then your going to have to get really good at traffic identification and QoS management.

If you don't really want traffic to be managed to that degree then simple bursts may work for you.

Re: Burst Time Calculation

Posted: Sun Oct 19, 2014 3:01 am
by tester
see attached XLS sheet which performs simulation of the burst behavior

Re: Burst Time Calculation

Posted: Sun Oct 19, 2014 9:25 am
by Kickoleg
Real Time = Treshold *( Burst Time/Burst Limit )