Cisco CRS Command Reference Manual page 51

Quality of Service Commands on the Cisco IOS XR Software
The match dscp command examines the higher-order six bits in the type of service (ToS) byte of the IP
header. Only one of the eight values is needed to yield a match (OR operation).
The command supports only eight IP DSCP values. If you try to configure more match statements after all
the eight values are matched, the statements get rejected.
The IP DSCP value is used as a matching criterion only. The value has no mathematical significance. For
instance, the IP DSCP value 2 is not greater than 1. The value simply indicates that a packet marked with the
IP DSCP value of 2 should be treated differently than a packet marked with an IP DSCP value of 1. The
treatment of these marked packets is defined by the user through the setting of QoS policies in policy map
class configuration mode.
Table 2: IP DSCP Reserved Keywords
DSCP Value
0
10
12
14
18
20
22
26
28
30
34
36
38
46
8
16
24
32
OL-23235-03
Cisco IOS XR Modular Quality of Service Command Reference for the Cisco CRS Router, Release 4.0
Reserved Keyword
default
AF11
AF12
AF13
AF21
AF22
AF23
AF31
AF32
AF33
AF41
AF42
AF43
EF
CS1
CS2
CS3
CS4
match dscp
45