Assigning a Class of Service to Policy Role

How a packet is treated as it transits the link can be configured in the CoS (Class of Service). It is through a CoS that Quality of Service (QoS) is implemented. A CoS can be configured for the following values:
  • 802.1p priority
  • IP Type of Service (ToS) rewrite value
  • Priority Transmit Queue (TxQ) along with a forwarding behavior
  • Inbound rate limiter per transmit queue
  • Outbound rate shaper per transmit queue

CoS configurations are identified by a numeric value between 0 - 255. 0 - 7 are fixed 802.1p CoS configurations. CoS configurations 8 - 255 are user configurable. Policy uses the cos option followed by the CoS configuration ID value to associate a CoS with a policy role.