H3C Technologies H3C S5120 Series Switches - Manual (Page 357)

3-3
Figure 3-1 Priority mapping procedure for an Ethernet packet
Which priority is
trusted on the
port?
Receive a packet
on a port
Use the port priority
as the 802.1p priority
for priority mapping
N
Look up the dot1p-
dscp and dot1p-lp
mapping tables
Mark the packet with
new DSCP
precedence and local
precedence
Is the packet
802.1q tagged?
Y
DSCP
in packets
Look up the dscp-lp,
dscp-dot1p, and dscp-
dscp mapping tables
802.1p
in packets
Mark the packet with
local precedence,
802.1p priority, and
new DSCP
precedence
Look up the dot1p-
dot1p, dot1p-dscp,
and dot1p-lp mapping
tables
Mark the packet with
new 802.1p priority,
new DSCP
precedence, and
local precedence
Schedule the packet
according to its local
precedence
Use the port
priority as the
802.1p priority for
priority mapping
Look up the dot1p-
dscp, and dot1p-lp
mapping tables
Mark the packet
with new DSCP
precedence and
local precedence
Port priority
Priority Mapping Configuration Tasks
You can modify priority mappings by modifying priority mapping tables, priority trust mode on a port, and
port priority.
You are recommended to plan QoS throughout the network before making QoS configuration.
Complete the following task to configure priority mapping:
Task Remarks
Configuring a Priority Mapping Table Optional
Configuring the Priority Trust Mode on a Port Optional
Configuring the Port Priority of a Port Optional
Configuring Priority Mapping
Configuring a Priority Mapping Table
Follow these steps to configure an uncolored priority mapping table:
To do… Use the command… Remarks
Enter system view system-view —