H3C S5820X Series Configuration Manual

Also see for s5800 series: Installation manual Instruction manual Command reference Quick start Troubleshooting guide

Contents

H3C S5820X Series Configuration Manual Manual pdf 43 page image

4-3Figure 4-1 Priority mapping procedure for an Ethernet packetWhich priority istrusted on theport?Receive a packeton a portUse the port priorityas the 802.1p priorityfor priority mappingNLook up the dot1p-dpand dot1p-lpmapping tablesMark the packet withlocal precedence anddrop precedenceIs the packet802.1q tagged?YDSCPin packetsLook up the dscp-dp,dscp-dot1p, and dscp-dscp mapping tables802.1pin packetsMark the packet with802.1p priority, dropprecedence, and newDSCP precedenceLook up the dot1p-lpMapping tableMark the packet withlocal precedenceLook up the dot1p-dpand dot1p-lp mappingtablesMark the packet withlocal precedence anddrop precedenceSchedule the packetaccording to its local anddrop precedenceUse the portpriority as the802.1p priority forpriority mappingLook up the dot1p-dp, and dot1p-lpmapping tablesMark the packetwith localprecedence anddrop precedencePort priorityThe priority mapping procedure presented above applies in the absence of priority marking. If prioritymarking is configured, the device performs priority marking before priority mapping. Depending on howyou have configured the device, the device then uses the re-marked packet-carried priority for prioritymapping or directly uses the re-marked scheduling priority for traffic scheduling . In this case, neitherthe priority trust mode configuration on the port nor the port priority configuration takes effect.Priority Mapping Configuration TasksYou can modify priority mappings by modifying priority mapping tables, the priority trust mode on a port,or the port priority.You should plan QoS throughout the network before configuring QoS.Complete the following task to configure priority mapping: