A technician connects a new computer to the internet and then opens the wiring closet.

A toner probe is a tool that can be used to trace and identify cables in a wiring closet. The technician can use a toner probe to find the cable that connects the new computer to the internet. A cable tester is a tool that can be used to check the continuity and quality of a cable. A loopback plug is a tool that can be used to test network ports or cables by sending and receiving signals from the same device. A punchdown tool is a tool that can be used to terminate wires into a patch panel or jack.