What specific port should be unblocked on the firewall for multicast audio transmission in a Dante network?

In a Dante network, multicast audio transmission primarily utilizes the User Datagram Protocol (UDP), and UDP port 4321 is specifically designated for this purpose. This port is essential for the functioning of Dante's discovery and session management protocols, as it facilitates the transmission of audio streams across the network.

When a firewall is in place, ensuring that this port is unblocked allows multicast audio data to be transmitted effectively without interruption. The other ports mentioned in the choices serve different purposes and are not specifically related to the multicast audio streams in the Dante environment. Therefore, enabling UDP port 4321 is critical for the proper operation of a Dante network, ensuring that devices can communicate and transfer audio data without being hindered by firewall restrictions.