H3C Technologies H3C WX3000E Series Wireless Switches - Manual (Page 29)

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• Drop precedence is used for making packet drop decisions. Packets with the highest drop
precedence are dropped preferentially.
• User precedence is the precedence that the device automatically extracts from a certain priority
field of the packet according to its forwarding path. The user precedence represents the 802.1p
precedence for Layer-2 packets and the IP precedence for Layer-3 packets.
Priority mapping tables
The device provides various types of priority mapping tables, or rather, priority mappings. By looking up
a priority mapping table, the device decides which priority value is to assign to a packet for subsequent
packet processing.
The default priority mapping tables (as shown in
Appendix A Default priority mapping tables ) are
available for priority mapping. They are adequate in most cases. If a default priority mapping table
cannot meet your requirements, you can modify the priority mapping table as required.
Priority mapping configuration tasks
You can configure priority mapping in any of the following approaches:
• Configuring priority mapping tables.
• Configuring priority trust mode. In this approach, you can configure a port to look up a certain
priority, 802.1p for example, in incoming packets, in the priority mapping tables. If no packet
priority is trusted, the port priority of the incoming port is used.
• Changing port priority. By default, all ports are assigned the port priority of zero. By changing the
port priority of a port, you change the priority of the incoming packets on the port.
• Configuring a QoS policy containing the priority mapping (simply called “primap”) action with the
primap command.
Perform these tasks to configure priority mapping:
Task Remarks
Configuring a priority mapping table Optional
Configuring a port to trust packet priority for priority mapping Optional
Changing the port priority of an interface Optional
Configuring primap Optional
Configuring priority mapping
Configuring a priority mapping table
The device provides the following types of uncolored priority mapping table.
• dot1p-dot1p: 802.1p-to-802.1p mapping table.
• dot1p-dscp: 802.1p-to-DSCP mapping table.
• dot1p-lp: 802.1p-to-local mapping table.
• dscp-dot1p: DSCP-to-802.1p mapping table, which applies to only IP packets.