QoS in Tunnel Interface

Unanswered Question
Aug 27th, 2009
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Hi Experts,

I request you to share the concept Why

"Cisco IOS logical interfaces (Tunnel Interface) do not inherently support a state of congestion and do not support the direct application of a service policy that applies a queuing method"

I know that a child policy-map X has to be created and and must be applied as a service policy in another policy-map Y

I tried and not able to get why it is not supported.

Thanks in advance


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snarayanaraju Thu, 08/27/2009 - 04:07
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Thanks for your reply. I am aware that it is virtual interface and do not support QoS natively.

My doubt is why the child policy-map is been insisted to be used to make QoS work?



Joseph W. Doherty Thu, 08/27/2009 - 04:59
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The child policy isn't needed unless you intend to support a CBWFQ policy. Then, since CBWFQ needs to "know" bandwidth, it uses a shaper, in a parent policy, to "define" the bandwidth, which the child policy then uses. (BTW, would need to double check, but the CBWFQ [HQF] starting with 12.4.20T, I recall, has some improved/changed support for tunnel QoS.)


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