Which of the following devices is primarily responsible for controlling data traffic within a network?

The primary responsibility of managing and directing data traffic within a network falls to a switch. A switch operates at the data link layer (Layer 2) of the OSI model, where it receives, processes, and forwards data to devices on the same local area network (LAN) based on their MAC addresses. This enables efficient communication between multiple devices by establishing a dedicated connection between the sender and receiver, thereby reducing collisions and increasing network performance.

Additionally, switches can utilize techniques such as VLANs (Virtual Local Area Networks) to segment networks and enhance security and efficiency. In a busy network, switches provide optimized data flow, ensuring that each device communicates effectively without unnecessary delays.

While routers also manage data traffic, they primarily operate at the network layer (Layer 3) and are designed to route data between different networks rather than within a single, local network. Hubs, on the other hand, transmit data to all connected devices without intelligence regarding the destination, leading to potential collisions and inefficiencies. Servers, while crucial for hosting services and data, do not control traffic flow in the manner that switches do. Thus, a switch plays the key role in directing traffic effectively within a network.