A high-speed Ethernet link behaves like a chain of dependent elements. The connector provides the physical interface at one or both ends, but the signal also travels through cable pairs, mating contacts, device ports, and installed routing paths. IEEE 802.3 provides the broad Ethernet technology framework, while structured cabling standards such as ISO/IEC 11801-1 show why cabling systems are treated as engineered systems rather than isolated parts. For an industrial M12 connection, the data path may include moving machinery, control cabinets, field devices, vibration, cable bending, moisture exposure, and nearby power equipment. These conditions do not make a rated connector irrelevant; they explain why a connector rating cannot be read as the whole performance story.