H3C Technologies H3C S10500 Series Switches - Manual (Page 34)

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• dot1p-lp: 802.1p-to-local priority mapping table.
• dscp-dot1p: DSCP-to-802.1p priority mapping table, which is applicable to only IP packets.
• dscp-dp: DSCP-to-drop priority mapping table, which is applicable to only IP packets.
• dscp-dscp: DSCP-to-DSCP priority mapping table, which is applicable to only IP packets.
• exp-dot1p: EXP-to-802.1p priority mapping table.
• exp-dp: EXP-to-drop priority mapping table.
The default priority mapping tables (see the chapter “Appendix A Default priority mapping tables”) are
available for priority mapping. In most cases, they are adequate for priority mapping. If a default priority
mapping table cannot meet your requirements, you can modify the priority mapping table as required.
Priority trust mode on a port
The priority trust mode on a port decides which priority is used for priority mapping table lookup. Port
priority was introduced to use for priority mapping in addition to priority fields carried in packets. The
H3C S10500 Switch Series provides the following priority trust modes:
• Using the 802.1p priority carried in packets for priority mapping.
• Using the DSCP carried in packets for priority mapping.
The priority mapping procedure varies with the priority modes. For more information, see Priority
mapping procedure .
Priority mapping procedure
On receiving an Ethernet packet on a port, the switch marks the scheduling priorities (local precedence
and drop precedence) for the Ethernet packet. This procedure is done according to the priority trust
mode of the receiving port and the 802.1q tagging status of the packet, as shown in Figure 5 .