H3C Technologies H3C S5120 Series Switches - Manual (Page 376)

8-3
DSCP value (decimal) DSCP value (binary) Description
14 001110 af13
18 010010 af21
20 010100 af22
22 010110 af23
26 011010 af31
28 011100 af32
30 011110 af33
34 100010 af41
36 100100 af42
38 100110 af43
8 001000 cs1
16 010000 cs2
24 011000 cs3
32 100000 cs4
40 101000 cs5
48 110000 cs6
56 111000 cs7
0 000000 be (default)
802.1p Priority
802.1p priority lies in the Layer 2 header and applies to occasions where Layer 3 header analysis is not
needed and QoS must be assured at Layer 2.
Figure 8-2 An Ethernet frame with an 802.1Q tag header
As shown in Figure 8-2 , the 4-byte 802.1Q tag header consists of the tag protocol identifier (TPID, two
bytes in length), whose value is 0x8100, and the tag control information (TCI, two bytes in length).
Figure 8-3 presents the format of the 802.1Q tag header. The Priority field in the 802.1Q tag header is
called the 802.1p priority, because its use is defined in IEEE 802.1p. Table 8-5 presents the values for
802.1p priority.