DSCP
default PHB:
000000
AF(确保转发) PHB(001,010,011,100)
001,010 AF11
001,100 AF12
001,110 AF13
010,010 AF21
010,10 AF22
010,110 AF23
011,010 AF31
011,100 AF32
011,110 AF33
100,010 AF41
100,100AF42
100,110 AF43
EF PHB(101)
101110
Class-selector PHB(IP precedence)
001,000 cs1
010,000 cs2
011,000 cs3
100,000 cs4
101,000 cs5
110,000 cs6
111,000 cs7