Advanced Placement (AP) Computer Science

Which aspect of networking allows for maintaining service when parts of the network fail?

1. Fault Tolerance

2. Scalability

3. Redundancy

4. Latency

The correct answer is: Fault Tolerance

Fault tolerance is a crucial characteristic of networking that ensures continuous service and operational capability even when parts of the network encounter failures. This is typically achieved through various strategies that allow the system to detect failures and re-route data or shift loads seamlessly. For instance, if a specific server goes down, fault tolerance mechanisms can automatically redirect requests to a backup server, thus maintaining uninterrupted service. In the context of networking, fault tolerance is vital for systems that require high availability, such as data centers or cloud services, because it helps mitigate the risk of downtime. It often involves redundancy, where multiple components perform the same function, but fault tolerance specifically refers to the overall system's ability to keep functioning in the face of those redundancies or other failures. Scalability refers to the system's ability to grow and manage increased workload, while redundancy, although related to fault tolerance, focuses on the provision of additional resources to ensure that there is a backup available. Latency measures the delay before a transfer of data begins, which does not pertain to the system's ability to maintain service in case of failures. Therefore, fault tolerance directly relates to maintaining service continuity, making it the correct answer.