117
DSCP value (decimal)
DSCP value (binary)
Description
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 40 An Ethernet frame with an 802.1Q tag header
As shown in
, the 4-byte 802.1Q tag header consists of the TPID (2 bytes in length), whose
value is 0x8100, and the TCI (2 bytes in length).
shows 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.
shows the values for 802.1p priority.
Figure 41 802.1Q tag header