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