This read-create object specifies the MAC address of the subscriber unit that the headend is instructing to move to a new downstream and/or upstream channel, and it must reference a MAC address currently known to the headend before the row can be activated. Admins set this as the first step of manually initiating a channel-override operation on a specific SU. For example, to move one problematic SU off a noisy channel, an admin would populate cwdxHeSuChOverMacAddress with that SU's MAC address before setting the row active.