I'm trying to get my head round the best way of doing a nested (child/parent) LLQ policy. The setup is a central site with 10mb MPLS circuit (connected via a 100mb interface). And 30 remote sites varying 1-5mb, in all totalling 40mb.
I read a few posts including http://forum.cisco.com/eforum/servlet/NetProf?page=netprof&forum=Network%20Infrastructure&topic=WAN%2C%20Routing%20and%20Switching&topicID=.ee71a06&fromOutline=&CommCmd=MB%3Fcmd%3Ddisplay_location%26location%3D.1ddfd061
and its still not clear to me how this would work.
For example, if I create child policies that match each remote site subnets, shape the traffic and include a sub-child that prioritises voice etc, that makes sense to me. However I have to have an overall shaping limit of 10mb. So it seems I'd end up having a 3 tier nested policy.
But the actual policy attached to the interface, would merely be shaping to 10mb and referencing another policy that split each site out (as per the link I added). So I'd have an extra policy over and above that link.
Now how would this work? If traffic hits the interface but remains under 10mb, I'm assuming the policy attached to the interface would never get congested and therefore never reference the child policies. So would voice still get priority? If it was congested, how would the queueing and prioritisation then work.
I haven't setout the config yet, but thought I'd just bounce the idea first before I end up going down the wrong path.