beautypg.com

Prioritizing cos and dscp 9, Prioritizing cos and dscp – Allied Telesis AT-FS970M Series User Manual

Page 1639

background image

AT-FS970M Switch Command Line User’s Guide

1639

Prioritizing CoS and DSCP

By default, the DSCP field in Layer 3 packets and the CoS field in Layer 2
frames are ignored by the software. In addition, Trust CoS is enabled by
default. To map a DSCP value to a queue on an egress port, use the
TRUST DSCP command, which is located in the Class Map mode. See
Table 207 and Table 208 for the default mappings. As you can see from
the tables, the highest egress queue is seven, which is assigned the
highest, CoS or DSCP, value.

Table 207. CoS Default Mapping

Egress

Queue

CoS Value

2

0

0

1

1

2

3

3

4

4

5

5

6

6

7

7

Table 208. DSCP Default Mapping

Egress

Queue

DSCP

Value

0

0 - 7

1

8 - 15

2

16 - 23

3

24 - 31

4

32 - 39

5

40 - 47

6

48 - 55

7

56 - 63