Ingress Vlan Swapping; Figure 46: Ingress Vlan Swapping - Alcatel-Lucent 7750 SR Manual

Ingress VLAN Swapping

This feature is supported on VPLS and VLL services where the end to end solution is built using
two node solutions (requiring SDP connections between the nodes).
In VLAN swapping, only the VLAN-id value is copied to the inner VLAN position. The Ethertype
of the inner tag will be preserved and all consecutive nodes will work with that value. Similarly,
the dot1p bits value of outer-tag will not be preserved.
CPE
Payload
DSLAM
The network diagram in
facing SAPs) every subscriber is represented by several QinQ SAPs with inner-tag encoding
service and outer-tag encoding subscriber (DSL line). The aggregation side (BRAS or PE facing
SAPs) the is represented by DSL line number (inner VLAN tag) and DSLAM (outer VLAN tag).
The effective operation on VLAN tag is to "drop inner tag at access side and push another tag at
the aggregation side".
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C-VLAN= application
C
Payload C L
SAP per DSL &
per application
Ingress PE

Figure 46: Ingress VLAN Swapping

Figure 46
L-VLAN= DSL line
MPLS network
Payload L Lb
Service per application
per DSLAM
Service per application
per DSLAM
describes the network where at user access side (DSLAM
Lb= VC label
D-VLAN= DSLAM
Payload L
SAP per
DSLAM
SAP per
Egress PE
DSLAM
7750 SR OS Services Guide
D
BRAS
Video
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