It would be useful to measure electrical parameters (such as I,U,R and perhaps L,C or other) at the end of the cable, when the other end is disconnected or connected, and analyze the physical layer of the Ethernet computer network. For example when you occur problems on a network adapter, packet losses, loops or get an electric shock when touch the metal parts of equipment.
Some clarifying questions:
- Is it possible to do this using one or several multimeters?
- If it's possible then what and where exactly measure (between the wires or pairs of the cable or relative to ground)?
- Could this give some additional and more detailed diagnostic information about the cable or NIC?