The top priority function forms an outgoing ATM cell from the incoming ATM cell payload without the payload of the incoming cell being routed to the queuing resource.

Thus, the incoming cell may be transmitted through a single output port (8) as many times as is desired.

The ATM switch receives the incoming cell from an ATM endpoint or another ATM switch.

Thus, an incoming cell which is to be multicast to multiple users will be multicasted using the single VPI/VCI.