What component is commonly included with a Data Service Unit (DSU) to manage interfaces?

The Channel Service Unit (CSU) is commonly included with a Data Service Unit (DSU) to manage interfaces primarily because it serves as a line termination device that connects the digital lines from the telephone company to the customer's network equipment. The CSU offers essential functions such as signal conditioning, line monitoring, and isolation which ensure that the data signals transmitted over the network maintain integrity and are error-free.

By working alongside the DSU, the CSU facilitates proper communication between the Data Terminal Equipment (DTE) and the external network. This combination allows for necessary synchronization and ensures that the data is properly formatted and delivered across the network infrastructure. Together, they function as an interface that converts and manages the data signals for effective transmission.

Other components listed, such as Data Terminal Equipment, signal repeaters, and network bridges, serve different purposes in a network environment. For instance, while DTE is the actual device that generates or receives the data, it does not perform the interface management functions provided by the CSU. Signal repeaters are used to extend the distance a signal can travel but do not manage interface connections. Network bridges, on the other hand, are essential for connecting and filtering traffic between different network segments but do not directly relate to the DSU's functionality