The value of tmnxMcacBdlChlType specifies the channel's type.
A channel with the value of 'mandatory' has higher priority than
a channel with the value of 'notMandatory'.
The combination of tmnxMcacBdlChlClass and tmnxMcacBdlChlType
is used to define the priority of channels. If there exists
channels with the same combination then round robin is used to
determine the channels that need to be dropped if any of the
CAC constraints are met.