The value of msapIgmpSnpgMcacLagPortsDown indicates
the configured number of ports in a lag group that are down.
If the number of ports available in the lag is reduced by the
number of ports configured for msapIgmpSnpgMcacLagPortsDown
object then bandwidth allowed for bundle will be updated to
the value of msapIgmpSnpgMcacLevelBW indexed by
msapIgmpSnpgMcacLagLevel value.