This is a bit map of VLAN.
in receiving order:
OCTET 1 OCTET 2 .....
xxxxxxxx xxxxxxxx .....
|| || |_ VLAN 8
|| ||
|| ||___ VLAN 7
|| |____ VLAN 6
||_________ VLAN 1
|__________ unused
where x : 1 - PIP is used for this VLAN.
x : 0 - PIP Not used for this VLAN.