Which of the following is NOT a type of network traffic?

The term "Bidirectional" is not classified as a type of network traffic. In networking, traffic types are primarily categorized based on how data is sent from one source to one or multiple destinations.

Unicast refers to traffic directed from one sender to one specific receiver, allowing for point-to-point communication. Broadcast is a type of communication where packets are sent from one sender to all potential receivers on the network segment, facilitating one-to-all communication. Multicast falls between these two, where data is sent from one sender to multiple specified receivers, but not to every device on the network.

In contrast, bidirectional describes the capability of communication channels or protocols to send and receive data in both directions, rather than being a type of traffic itself. This term is often associated with communication flow rather than classification of network traffic types. Therefore, it rightly stands out as not fitting the same category as the other traffic types listed.