User's Manual

Liberator-V1000 User Manual Rev 04v05
Page 41 of 85 FBN Doc #: FBN-0125_04v05
Figure 44 - VLAN filtering with Management VLAN ID 99
5.4.2.4 Case 3b: VLAN’s used with VLAN for management and default VLAN (Tag / Untag)
This case is the same as Case 3a, but with the additional step of performing Tag / Untag manipulation on a
single VLAN ID only. In this scenario, one of the User Traffic VLAN’s is also specified to be the DEFAULT VLAN
at one end of the link only: at the end where the DEFAULT VLAN is enabled, all incoming untagged frames
into the Ethernet port will be tagged with the VLAN ID of the DEFAULT VLAN before sending over the air to
the remote side as Tagged frames. All frames Tagged with the DEFAULT VLAN ID which arrive over the air
from the remote terminal will be stripped of their VLAN Tag before being sent out on the Ethernet port as
Untagged frames. Note that both ends of the link must contain the same list of VLAN ID’s in the “Allowed
VLAN’s” table, but the DEFAULT VLAN can only be enabled at one end of the link at any one time. See the
figures below, where VLAN ID 99 is used for Management, VLAN ID’s 10, 11 and 12 for User Traffic, with
VLAN ID 10 being set as the DEFAULT VLAN, and therefore performing the Tag / Untag operation on
Terminal “B”.
Note that it is possible to configure a DEFAULT VLAN ID at both ends of the link, (which may not be identical),
but this represents an unlikely network configuration and is therefore normally unnecessary.