H3C S7500E Series - Page 46

4-3
Figure 4-1 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 of
the packet
Look up the
dot1p-dp and
dot1p-lp tables
Mark the packet
with local
precedence and
drop precedence
Is the packet
802.1q tagged?
DSCP in packets
Look up the
dscp-dp, dscp-
dot1p, and dscp-
dscp tables
802.1p in
packets
Mark the packet
with 802.1p
priority, drop
precedence, and
new DSCP
precedence
Look up the
dot1p-lp table
Mark the packet
with local
precedence
Look up the
dot1p-dp and
dot1p-lp tables
Mark the packet
with local
precedence and
drop precedence
Schedule the packet
according to its local
precedence and drop
precedence
Y
N
For an MPLS packet, the priority mapping procedure as shown in
Figure 4-2 is adopted: