Interface-level MCAC constraints are applied to the interface on which the join was received. Mandatory and optional channels are allowed under the following conditions.
Mandatory channels—The bandwidth for the already-accepted mandatory channels plus the bandwidth of this channel cannot be greater than the configured mandatory bandwidth on this interface.
Optional channels—The bandwidth for the already-accepted optional channels plus the bandwidth of this channel cannot be greater than the configured amount of unconstrained bandwidth less the configured amount of mandatory bandwidth on this interface.