P Priority - 3Com S7906E Configuration Manual

DSCP value (decimal)
0

802.1p Priority

802.1p priority lies in Layer 2 packet headers and is applicable to occasions where Layer 3 header
analysis is not needed and QoS must be assured at Layer 2.
Figure 13-2 An Ethernet frame with an 802.1Q tag header
As shown in Figure
bytes in length), whose value is 0x8100, and the tag control information (TCI, two bytes in length).
Figure 13-3 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.
for 802.1p priority.
Figure 13-3 802.1Q tag header
Table 13-22 Description on 802.1p priority
802.1p priority (decimal)
0
1
2
3
4
5
6
7
DSCP value (binary)
000000
13-2, the 4-byte 802.1Q tag header consists of the tag protocol identifier (TPID, two
802.1p priority (binary)
000
001
010
011
100
101
110
111
13-11
Description
be (default)
Table 13-22 presents the values
Description
best-effort
background
spare
excellent-effort
controlled-load
video
voice
network-management