hi
i want to share 12meg internet between 3 groups of users which have different ip ranges,each group should given different bandwidths.
but it is important to define a way to sharing bandwidth between them if forexample one group is absent,and this sharing should be according to priorities that we had defined.
the works i did:first i defined a parent queue an added 3 queses in it and for each queue i entered limit at and max limit items,then add default pcq down and upload.i dont know what to do for sharing all bandwith in absence of one group?
i want to do this by defining prioity but in this case,at first step all bandwith will be used by group with high priority .
help me pleaseeeeeeeeee 
