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Class of Service (CoS) is use to classify the traffic at layer 2 (Data link layer). CoS can defined by manipulating 3-bit field present in the ethernet frame header. It specifies a priority value between 0 and 7 so that Quality of Service (QoS) can use this priority value to differentiate and shape or police the network traffic. QoS guarantees are required to ensure proper operation of communication based application, for example voice and video. A switch will serve many incoming queues by transmitting packets arriving at these queues through one output port, each of those packets should be marked with QoS.
The objective of this article is to show you how to apply CoS to Queues.
• ESW500 Series Switches
Step 1. At the Switch Configuration Utility, choose Quality of Service > General > CoS/802.1p to Queue. The CoS to Queue page opens:
Step 2. For a given Class of Service value choose a particular queue from the Queue drop-down list next to it. CoS values will be in the range 0-7, where 0 is the lowest priority and 7 is the highest priority. Queue values will be in the range 0-4.
Step 3. (Optional) To apply the default values check the Restore Default check box.
Step 4. Click Apply. The required CoS values are mapped to the Queues.