The value of tMacFilterParamsLowISID specifies the lowest value of the
24 bit (0..16777215) service instance identifier for this service that
matches this entry.
The default value of -1 indicates no ISID matching will be performed.
The value of this field can be equal to but not lower than the value
of the tMacFilterParamsHighISID field.
Changing the value of this field might also change the value of
tMacFilterParamsHighISID:
A value of -1 will change the value of tMacFilterParamsHighISID to -1.
Changing the value of this field from -1 to any other value will change
the value of tMacFilterParamsHighISID to this same value.
Note that tMacFilterParamsLowISID and tMacFilterParamsHighISID can only
be set if tMacFilterType is set to 'isid(1)'.