Microsens MS453490M Management Guide User Manual

Page 230

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C

HAPTER

11

| Class of Service

Layer 3/4 Priority Settings

– 230 –

C

OMMAND

U

SAGE

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

page 228

), and the ingress packet type is IPv4.

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.

The specified mapping applies to all interfaces.

P

ARAMETERS

These parameters are displayed:

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)

Table 15: 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.

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