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New Member

Low latency queueing -- best practices/limitations

I recall reading or hearing somewhere that there was a practical restriction, or at least a best practice, regarding priority queueing for voice across WAN links.

I thought that you cannot, or should not, build QOS parameters to allocate >20% of the WAN bandwidth to voice traffic. I thought it was a limitation on the low-latency queueing buffers or something. Now, of course, I can't find any documentation to that effect.

So here's the question: is there a hard limit or a best practice limitation on how much bandwidth you should allocate to the voice priority queue?

New Member

Re: Low latency queueing -- best practices/limitations

Cisco Technical Marketing testing has shown a significant decrease in data application response times

when realtime traffic exceeds one-third of link bandwidth capacity. Extensive testing and customer

deployments have shown that a general best queuing practice is to limit the amount of strict priority

queuing to 33 percent of link capacity. This strict priority queuing rule is a conservative and safe design

ratio for merging realtime applications with data applications.

Hope that helps


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