User`s manual

Intelligent 4 Band VDSL 24 Ports Managed IP DSLAM USER’S MANUAL Ver. A.1
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Ingress Filtering
Ingress filtering lets frames belonging to a specific VLAN to be forwarded if the port belongs to that VLAN.
VDSL IP DSLAM has two ingress filtering rule as follows:
Ingress Filtering Rule 1: Forward only packets with VID matching this port's configured VID.
Ingress Filtering Rule 2: Drop Untagged Frame.