I have the Cisco Press QOS book and here is a snippet: Pg. 297
"the policy-map queue-voip policy assigns VOIP traffic 50 percent of the bandwidth based on the bandwidth 50 percent command. But 50 percent of what? Well, the actual bandwidth is derived from the percentage of the bandwidth configured on the bandwidth interface subcommand. In this case, the bandwidth is set to 128, so the voip-rtp class gets 64k..."
So this quote tells me that when you assign a bandwith percentage in a policy map, the actual value is related to what you have put in as a bandwidth statement on the interface.
But I was working with a Provider on an upcoming MPLS project and they showed a quote saying that the bandwidth statement on the physical interface was optional and had nothing to do with the QOS policy-map configurations. In particular, they were talking about a MLPPP link.
My question: are virtual links treated differently than physical links as far as QOS policy-maps?
The reason we were even asking about this was that another engineer asked what would happen if we configured 6Mb as a bandwidth statement on a 4xT1 MLPPP interface, and one of the links dropped out? Would QOS CBWFQ still use the 6Mb as a reference or would it know that the actual bandwidth had changed to 4.5Mb?
If anyone has any guidance, it would be greatly appreciated. If you know of a link or two that addresses my question, save yourself the typing and I'll do the research :)
Thanks in advance,