The value of vRtrIgmpGrpIfMcacUnconstrainedBW specifies the bandwidth
assigned for all SAPs belonging to this group-interface's multicast
CAC policy traffic in kilo-bits per second(kbps).
If the default value of '-1' is set, there is no constraint on bandwidth
allocated to the group-interface.
If the value of vRtrIgmpGrpIfMcacUnconstrainedBW is set to '0' and if
a multicast CAC policy is assigned on the group-interface, then
no group (channel) from that policy is allowed on a SAP belonging to
that group-interface.