Which method is NOT useful for identifying the type of cable?

Identifying the type of cable is crucial for network setup and maintenance. Among the methods listed, testing the network speed is not a direct approach to determining the cable type. While network speed tests can provide insight into the performance of the cable in use, they do not reveal specifics about the cable itself, such as whether it is coaxial, twisted pair, or fiber optic.

In contrast, visual inspection of connectors can help identify the type of cables based on the design and shape of the connectors—such as RJ45 for Ethernet cables or LC/SC for fiber optics. Using a cable tester allows for checking the integrity and functionality of the cable, often providing information about the cable category and whether it's functioning correctly. Similarly, a media tester or certifier can offer detailed specifications about the cable type and its performance capabilities, ensuring it meets necessary standards.

Therefore, while speed testing may give performance metrics, it does not provide the necessary information to categorize the cable type effectively.