How many pairs of wires are used in a 1000BASE-T cable?

In a 1000BASE-T cable, which is part of the Gigabit Ethernet standard, all four pairs of wires are utilized. This standard uses Category 5e or higher cables and supports data transmission at speeds of 1 Gbps over standard twisted-pair cabling. Each pair of wires is responsible for carrying communications in both directions, utilizing a method known as four-pair transmission.

By employing all four pairs, 1000BASE-T can achieve its high data transfer rates through the use of advanced signaling techniques, namely PAM-5 (Pulse Amplitude Modulation with 5 levels). This technique allows for the simultaneous transmission of multiple data streams over the same cable, further optimizing bandwidth utilization. Thus, recognizing that 1000BASE-T employs all four pairs is crucial for understanding its functionality and performance in networking environments.