netsys G.SHDSL.bis 3010E User Manual page 32

3010E/3020E/3040E G.SHDSL.bis EFM Bridge Modem User's Manual Ver:A2
performance through reduced broadcast traffic. VLAN groups can be modified at any time by adding, moving
or changing ports without any re-cabling.
Before enabling VLANs for the EFM modem, you must first assign each port to the VLAN group(s) in which it
will participate. By default all ports are assigned to VLAN1 as untagged ports. Add a port as a tagged port if
you want it to carry traffic for one or more VLANs, and any intermediate network devices or the host at the
other end of the connection supports VLANs. Then assign ports on the other VLAN-aware network devices
along the path that will carry this traffic to the same VLAN(s), either manually or dynamically using GVRP.
However, if you want a port on this EFM modem to participate in one or more VLANs, but none of the
intermediate network devices nor the host at the other end of the connection supports VLANs, then you
should add this port to the VLAN as an untagged port.
Note: VLAN-tagged frames can pass through VLAN-aware or VLAN-unaware network
Inter-connection devices, but the VLAN tags should be stripped off before passing it on to any end-node host
that does not support VLAN tagging.
VLAN Classification – When the EFM modem receives a frame, it classifies the frame in one of two ways. If
the frame is untagged, the EFM modem assigns the frame to an associated VLAN (based on the default
VLAN ID of the receiving port). But if the frame is tagged, the EFM modem uses the tagged VLAN ID to
identify the port broadcast domain of the frame.
Port Overlapping – Port overlapping can be used to allow access to commonly shared network resources
among different VLAN groups, such as file servers or printers.
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