Table 163 – Brocade Communications Systems Brocate Ethernet Access Switch 6910 User Manual
Page 847
Brocade 6910 Ethernet Access Switch Configuration Guide
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53-1002581-01
Layer 3/4 Priority Settings
38
Command Usage
•
Enter per-hop behavior and drop precedence for any of the DSCP values 0 - 63.
•
This map is only used when the priority mapping mode is set to DSCP (see
), and the
ingress packet type is IPv4. Any attempt to configure the DSCP mutation map will not be
accepted by the switch, unless the trust mode has been set to DSCP.
•
Two QoS domains can have different DSCP definitions, so the DSCP-to-PHB/Drop Precedence
mutation map can be used to modify one set of DSCP values to match the definition of another
domain. The mutation map should be applied at the receiving port (ingress mutation) at the
boundary of a QoS administrative domain.
•
Random Early Detection starts dropping yellow and red packets when the buffer fills up to
0x60 packets, and then starts dropping any packets regardless of color when the buffer fills up
to 0x80 packets.
Parameters
These parameters are displayed:
•
Port – Specifies a port.
•
DSCP – DSCP value in ingress packets. (Range: 0-63)
•
PHB – Per-hop behavior, or the priority used for this router hop. (Range: 0-7)
•
Drop Precedence – Drop precedence used for Random Early Detection in controlling traffic
congestion. (Range: 0 - Green, 3 - Yellow, 1 - Red)
Interface
To map DSCP values to internal PHB/drop precedence:
1. Click Traffic, Priority, DSCP to DSCP.
2. Select Configure from the Action list.
3. Select a port.
TABLE 163
Default Mapping of DSCP Values to Internal PHB/Drop Values
ingress-
dscp1
ingress-
dscp10
0
1
2
3
4
5
6
7
8
9
0
0,0
0,1
0,0
0,3
0,0
0,1
0,0
0,3
1,0
1,1
1
1,0
1,3
1,0
1,1
1,0
1,3
2,0
2,1
2,0
2,3
2
2,0
2,1
2,0
2,3
3,0
3,1
3,0
3,3
3.0
3,1
3
3,0
3,3
4,0
4,1
4,0
4,3
4,0
4,1
4.0
4,3
4
5,0
5,1
5,0
5,3
5,0
5,1
6,0
5,3
6,0
6,1
5
6,0
6,3
6,0
6,1
6,0
6,3
7,0
7,1
7.0
7,3
6
7,0
7,1
7,0
7,3
The ingress DSCP is composed of ingress-dscp10 (most significant digit in the left column) and
ingress-dscp1 (least significant digit in the top row (in other words, ingress-dscp = ingress-dscp10 * 10 +
ingress-dscp1); and the corresponding internal-dscp is shown at the intersecting cell in the table.
The ingress DSCP is bitwise ANDed with the binary value 11 to determine the drop precedence. If the
resulting value is 10 binary, then the drop precedence is set to 0.