Summary:Learn how to use the Cisco three-layer hierarchical model to properly roll out QoS in your Cisco switched network. Keywords:cisco, ccnp, exam, pass, bcmsn, switch, quality, of , service, qos, core, access, distribution, ccie Article Body:QoS is a big topic on your BCMSN and CCNP exams, and for good reason.  As more and more traffic flows through today's networks, accurately...