Objective

Differential Services Code Point (DSCP) is the evaluation of the QoS level of the packet at Layer 3. The out of profile packets is the portion of the traffic flow that exceeds the QoS specified limit. The policer, which is assigned to class maps, specifies the action to be taken on this traffic.

If the traffic flow exceeds the QoS specified limit and if this exceed action is due to out of profile DSCP, then the switch remaps the original value with the new value of the out of profile IP packets. It also physically replaces the original values with new DSCP values in the out of profile packets.

The objective of this document is to explain how to configure out of profile DSCP mapping on the switch.

Applicable Devices

• Sx500 Series Stackable Switches

Software Version

• 1.3.0.62

Configuration of Out of Profile DSCP Mapping

Step 1. Log in to the web configuration utility to choose Quality of Service > QoS Advanced Mode > Out of Profile DSCP Mapping. The Out of Profile DSCP Mapping page opens:

Take an example in which there are three levels of QoS services which are provided (Silver, Gold and Platinum services). The incoming DSCP values that are given to these services are 100, 200 and 300 respectively. If such traffic is forwarded to another service provider who uses the same levels of traffic but the DSCP values which are used to indicate this traffic are 400, 500 and 600, then the Out of Profile Mapping changes the incoming values when they are mapped to the outgoing values. The Out of Profile DSCP Mapping page allows the user to change the DSCP value of the incoming and outgoing traffic of the switch. DSCP In shows the DSCP value of the packet that is coming in and which needs to be mapped to an alternate value.

Step 2. Choose the DSCP Out value to where the incoming value is mapped from the drop-down list.

Step 3. Click Apply to update the running configuration file.

Note: If Restore Defaults is clicked, the default values are restored.