I am using Canopy v7.36 at present on Classic hardware using HWS.
I would like to offer a service level that gives the user a burst of data. Ideally, this would be a committed rate of 512k and a burst of 1024k.
I have done some experimentation with the MIR and CIR settings, but the best I can get is a very short (1-2sec) burst.
Am I missing something? Is it possible to have a meaningful duration for this burst?
Regards,
John
you need to understand what the burst is, its not data rate its data.
If you give some one CIR of 512 that is 512kbps for aslong as they want, when you give them a burst of 1024kb that is just 1024kb of data,
that could be a 1024kbps extra for 1 sec, 512kps extra for 2 sec, 256kbps for 4 secs, etc… once the user has got 1024kb of data then the burst becomes ineffective.
If you read the user guide it explains the token buckets. The bucket is charged once the subscriber is pulling less then their CIR, emptied for the burst and recharged when they pull less then CIR.
I fuller explanation is given in the user guide.
Burst is a size and CIR/MIR is a rate.
Burst is listed in Bytes (B) so once that bucket is empty then the user with transmit at the rates you assigned.
Keep in mind that if you set these values via BAM then you must select BAM as the configuration source. If you are setting these values on the SM then you must set SM as the configuration source.
I explained this to my CEO by describing the rate as a hose and the burst as bucket.
The hose will continuously pass a volume up to the limitation of the pipe.
The bucket holds somewhere between nothing and a equal to the size of the bucket and is dumped periodically (the frequency at which this bucket is emptied will vary according to number of control slots and AP-SM sessions – the reservation scheme breaks at 200 sessions and thus the sales notion of “up to 200 SM / AP” ).
If you want a fixed rate, set the rate & bucket size to the same value.
Setting a slightly larger bucket size will yield short duration bursts that will improve your scores on most of the web based test sites. Using a very large bucket will decrease your up sale success as customers will perceive their bandwidth to be greater than their service rate (remember that customers are also dealing with a bucket variable in their TCP/IP stack).
To obtain a truly variable burst that can be permitted at night and not during peak, buy a bandwidth shaper.
nice analogy
Ditto…I’ve always used the bucket in the explaination but never the hose.