Class of Service (CoS) is used to classify the traffic at layer 2 (Data link layer). CoS can defined by manipulating the 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 applications, 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 map CoS values to queues.
• SFE/SGE Managed Switches
• v3.0.2.0
Step 1. Log in to web configuration utility and choose Quality of Service > General > CoS to Queue. The CoS to Queue page opens:
Step 2. For a given Class of Service value choose a particular queue value from the Queue drop-down list next to it. CoS values are in the range 0-7, where 0 is the lowest priority and 7 is the highest priority. Queue values are 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.
Caution: This only saves your configuration to the running configuration file. This means any changes made will be lost if the device is rebooted. If you wish to save these changes even after a system reboot, you need to copy the running configuration file to the startup configuration file. See Copy Configuration File on SFE/SGE Series Managed Switches for more information on how to do this.