7-2 
Table 7-2 Description on DSCP values 
DSCP value (decimal)  DSCP value (binary)  Description 
46 101110 ef 
10 001010 af11 
12 001100 af12 
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 is applicable to occasions where Layer 3 header analysis 
is not needed and QoS must be assured at Layer 2. 
Figure 7-2 An Ethernet frame with an 802.1Q tag header 
 
 
As shown in 
Figure 7-2, 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 7-3 presents the format of the 802.1Q tag header. The Priority field in the 802.1Q tag header is