Operation Manual – QoSH3C S7500 Series Ethernet Switches Chapter 1 QoS Configuration1-15Note:For LPUs that are not of A-type, if you specify the trusted priority for adding packets tooutput queues by using the priority-trust dscp or priority-trust ip-precedencecommand, the switch will convert the DSCP precedence or IP precedence of thereceived packets to the corresponding CoS precedence according to the DSCP-CoSprecedence mapping table or IP-CoS precedence mapping table and then add thepackets to the corresponding queues by CoS priority. In this case, the precedence isconverted as follows.z DSCP precedence 0 through 7 are mapped to CoS precedence 2; 8 through 15 toCoS precedence 0; 16 through 23 to CoS precedence 1; 24 through 31 to CoSprecedence 3; 32 through 39 to CoS precedence 4; 40 through 47 to CoSprecedence 5, 48 through 55 to CoS precedence 6; 56 through 63 to CoSprecedence 7.z IP precedence 0 is mapped to CoS precedence 2; IP precedence 1 to CoSprecedence 0; IP precedence 2 to CoS precedence 1; IP precedence 3 to CoSprecedence 3. The others are as those listed in Table 1-7.1.4.1 Setting the Priority According to Which a Packet is Put into an OutputQueueYou can select a type of priority as the basis for a packet to be put into an output queueon a port as required.I. Configuration prerequisitesThe priority according to which a packet is put into an output queue is specified.II. Configuration procedureFollow these steps to set the priority according to which a packet is put into an outputqueue:To do… Use the command… RemarksEnter system view system-view —Configure the priorityaccording to which apacket is put into anoutput queuepriority-trust { dscp |ip-precedence | cos |local-precedence }RequiredBy default, a queue is putinto an output queue on aport according to the localprecedence of the packet.
