A DMVPN network is being deployed for 10 branch sites to connect to the central headquarters over the Internet. Each branch site connects to the internet via a 1.5 Mb/s ADSL line, and the headquarters

Rate-limiting (policing) discards excess packets rather than buffering and scheduling them, causing unnecessary drops and providing no ability to prioritize critical traffic within the constrained bandwidth.

HQoS uses a parent shaper policy to rate the HQ output to 20 Mb/s (matching the SP-imposed limit) and child policies attached per-spoke tunnel to ensure HQ never bursts traffic toward any branch beyond the 1.5 Mb/s the branch ADSL can accept, while also enabling DSCP-based prioritization within each spoke's allocation.

A flat shaping policy applied only to the 20 Mb/s aggregate does not address per-spoke fairness or the 1.5 Mb/s branch constraint, leaving individual spokes vulnerable to starvation or over-subscription.

QoS is required because the aggregate HQ uplink (20 Mb/s) can easily overwhelm individual branch ADSL lines (1.5 Mb/s each), and without per-spoke shaping critical traffic will be dropped at the branch access loop.