Alcatel-Lucent 7450 Configuration Manual page 456

Filter Policy Advanced Topics
Arbitrary Bit Matching of VID Filters
In addition to matching an exact value, a VID filter mask allows masking any set of bits. The
masking operation is ((value & vid-mask) = = (tag and vid-mask)). For example: A value of 6 and
a mask of 7 would match all VIDs with the lower 3 bits set to 6. VID filters allow explicit matching
of VIDs and matching of any bit pattern within the VID tag.
When using VID filters on SAPs only VID filters are allowed on this SAP. Filters of type normal
and ISID are not allowed.
An additional check for the "0" VID tag may be required when using certain wild card operations.
For example frames with no tags on null encapsulated ports will match a value of 0 in outer tag and
inner tag because there are no tags in the frame for matching. If a zero tag is possible but not
desired it can be explicitly filtered using exact match on "0" prior to testing other bits for "0".
Note that configure>system>ethernet>new-qinq-untagged-sap is a special QinQ function for
single tagged QinQ frames with a null second tag. Using this in combination with VID filters is not
recommended. Note that the outer-tag is the only tag available for filtering on egress for frames
arriving from MPLS SDPs or from PBB services even though additional tags may be carried
transparently.
Page 456 7450 ESS Router Configuration Guide