Hi Wafik, Thanks for your great comments, just a little confuse for the two command" priority-queue output" and " srr-queue bandwidth shape" My question is if "regarding that enabling the priority (expedite) queue will exclude queue 1 from the SRR shaping and sharing." why there is a example in the Cisco document showing "priority-queue output " and "srr-queue" command under the same interface? Does it mean "priority-queue output" need to work with "srr-queue bandwidth shape" together.
priority-queue output: enable priority queue function srr-queue bandwidth shape: limit the bandwidth of priority queue. Please correct me, if I am wrong. Thanks. Cheers, Vincent 2010/8/4 Daniel Berlinski <dberlin...@gmail.com> > Thanks very much for this. I will read more carefully about this topic > looking carefully for the words in the documentation I could not find to > come with some conclusion as yours. Your answer makes sense and it is very > objective and I appreaciate that because this topic has beend discussed many > times here but with very loose ideas. > > Do you mind sharing with us what path led you to this conclusion? Was it a > document you read that explicitly said that the buffers are used to store > the excess traffic and not to provide the physical " pool" of memory > allocation to be used to each queue? > > Again I thank you for your objective and illustrative help! > Daniel > > On Wed, Aug 4, 2010 at 1:59 AM, Wafik Maher <wafikma...@gmail.com> wrote: > >> Hi Daniel, >> >> >> >> I absolutely agree with you on the first part, regarding that enabling the >> priority (expedite) queue will exclude queue 1 from the SRR shaping and >> sharing. >> >> However, I don’t think that it is possible to control the bandwidth >> percentages using the buffer size allocation “mls qos queue-set output 1 >> buffers 10 10 26 54”, simply because of the fact that the buffer is used to >> store the excess traffic when the input rate is higher than the output rate >> of a certain traffic. >> >> >> >> To illustrate my point let me introduce an example >> >> 3750 fastethernet (100Mb) >> >> 10 % are allocated to priority traffic >> >> 50 Mb Average Total Input rate of priority traffic >> >> >> >> On the above example, at the output the priority traffic can >> (theoretically) go up to full link speed 100 Mb, so apparently the input >> rate is not exceeding the output rate and the average output rate would be >> equal to the input which is 50 Mb (50 % not just the 10 % of the buffer >> size). As a matter of fact the buffer in this case is not expected even to >> fill the 10 %, it would just fill a small percent to accommodate with >> traffic spikes and the small processing delay. >> >> _______________________________________________ >> For more information regarding industry leading CCIE Lab training, please >> visit www.ipexpert.com >> >> > > _______________________________________________ > For more information regarding industry leading CCIE Lab training, please > visit www.ipexpert.com > >
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