Class of Service (CoS)

You implement QoS features in a Class of Service (CoS). How the firmware treats a packet as it transits the link depends upon the priority and forwarding treatments configured in the CoS. Up to 256 unique CoS entries can be configured. CoS entries 0–7 are configured by default with an 802.1p priority assigned and default forwarding treatment. For purposes of backward compatibility, CoS entries 0–7 cannot be removed. CoS entries 8-255 can be configured for the following services:

• 802.1p priority
• IP ToS rewrite value
• Priority Transmit Queue (TxQ) with configurable forwarding behavior
• In-bound (IRL) rate limiter per transmit queue
• Outbound (ORL) rate limiter per transmit queue (S-, K-Series)
• Outbound rate shaper per transmit queue

The CoS configuration for each service can be easily viewed using the CoS setting tables. Ports are bundled into port groups with the group assigned to a CoS, significantly cutting down on operational overhead and complexity.