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Limits

Posted: Thu Jul 15, 2004 12:15 am
by GJS
Can someone explain what the function of the various simple queue limits are? I do not understand these explanations from the manual:

limit-at - allocated stream data rate
max-limit - maximal stream data rate
total-limit-at - allocated total (bidirectional) stream data rate
total-max-limit - maximal total (bidirectional) stream data rate
burst-limit - maximal allowed burst of data rate in form of in/out
burst-threshold - average burst threshold in form of in/out
burst-time - burst time in form of in/out
total-burst-limit - maximal allowed total (bidirectional) burst of data rate
total-burst-threshold - Total (bidirectional) average burst threshold
total-burst-time - total (bidirectional) burst time

To sumarise:

1. What is the difference between allocated stream rate and maximal rate?
2. What is burst limit, burst threashold and burst time?

Thanks,
Guy

Posted: Thu Jul 15, 2004 12:54 am
by lastguru
Please read http://www.mikrotik.com/docs/ros/2.8/ro ... main.1.4.2 - it answers all your questions best way one can explain

Posted: Thu Jul 15, 2004 9:35 am
by Bill
The Target Address is the IP you are controlling the speed for. The bandwidth limits are in the format upload/download. Leave Destination address at 0.0.0.0/0, queue type as default.

The Limit-At setting is the minimum allocated speed for the queue.
The Max-Limit setting is the maximum allocated speed for the queue.
The Burst-Limit setting is the speed limit allowed above maximum.
The Burst-Threshold is the speed at which the time counter starts.
The Burst-Time is how long they are allowed to stay above the Burst-Threshold before being dropped back down to the Max-Limit.

For Example, a Simple Queue with the following settings:
Limit At: 65536/131072
Max Limit: 262144/524288
Burst Limit: 393216/786432
Burst Threshold: 262144/524288
Burst Time: 240

This will give the client a 64/128k slice of the available bandwidth. Their connection is limited at 256/512k. They are allowed to burst up to 384/768k. If they sustain a connection above 256/512k for more than 240 seconds, they are throttled back and held at 256/512k until they drop below that speed. The counter then restarts and they are able to burst above their regular limit again.

The Burst feature is nice because it allows fast web-browsing and email retrieval, and makes your service seem much quicker. The Burst Time can be adjusted so things like Windows Updates download much quicker, but the user can't hog the pipe downloading an ISO or something large.

Posted: Thu Jul 15, 2004 4:10 pm
by GJS
Thanks, Bill, this is just what I needed. Sorry for being generally dumb but in your example, I can't see the significance of Limit At speed. Under what circumstances does the customer get 64/128k?

Thanks,
Guy

Posted: Fri Jul 16, 2004 1:56 am
by Bill
The Limit-At speed is the guaranteed minimum speed the customer should get. If the router is heavily loaded and can't provide the 256/512, it will try to give the customer at least 64/128k. If you leave Limit-At blank, then it is a best-effort service and the customer gets whatever is available.

Posted: Fri Jul 16, 2004 4:00 pm
by GJS
Got it, Bill, thanks.

Guy