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Brocade Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide (Supporting R05.6.00) User Manual

Page 554

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530

Multi-Service IronWare Multiprotocol Label Switch (MPLS) Configuration Guide

53-1003031-02

How MPLS VLL works

4

W = mapped COS from internal priority (Z contributes to internal priority) using the COS encode
table

X = original outer VLAN COS

Y = original inner VLAN COS

Z = incoming EXP bits as described by Tunnel / VC label column = V or internal priority

or in the Tunnel/VC label column differentiates the behavior between when qos exp encode
policy is ON (default) or OFF.

or in the Outgoing packet Outer VLAN column differentiates the behavior between when qos
pcp encode policy is ON (default) or OFF.

CoS behavior for VLL raw mode

NOTE

This section assumes that the user understands how QoS works.

Table

83

describes the expected Class of Service (CoS) behavior for VLL packets when VLL raw

mode is in effect.

TABLE 83

Expected class of service behavior for VLL raw mode

VLL endpoints

Incoming packet

MPLS cloud

Outgoing packet

Outer VLAN

Inner VLAN

Tunnel/VC
label (Z)

Payload tag

Outer VLAN

Inner VLAN

Dual-tagged
to dual-tagged

X

Y

V or internal
priority

N/A

W or Z

Z

Single-tagged
to dual-tagged

X

N/A

Z

Untagged to
dual-tagged

N/A

N/A

Z

Dual-tagged
to
single-tagged

X

Y

N/A

NOTE

For more specific examples of CoS behavior for raw mode, see

“Example 1: CoS behavior for

dual-tagged to dual-tagged VLL endpoints”

on page

531 and

“Example 2: CoS behavior for

dual-tagged to single-tagged VLL endpoints”

on page

532.

Legend for Table 83

V = mapped EXP bits from internal priority (X contributes to internal priority) using the EXP
encode table.

W = mapped COS from internal priority (Z contributes to internal priority) using the COS encode
table.

X = original outer VLAN COS

Y = original inner VLAN COS

Z = incoming EXP bits as described by Tunnel / VC label column = V or internal priority