Kind of twisted-pair lines should be on?
Standard UTP cable should be 4 lines.
Only required when using twisted-pair cable as a transmission medium 2 pair (4 cores) line that can send and receive signals. Use twisted-pair cable as a transmission medium, fast network, there are three standards, 100Base-TX, and 100Base-T2 and 100Base-T4. Among them, the standard requires the use of all 4 100Base-T4 to signal transmission lines, two standard requires only 2 pairs of lines. 100Base-TX is the most popular standard in fast network, so we purchased when using twisted 100M network, not to use only 2 pairs of twisted-pair cable. United States standard cable (AWG) class 3, class 4, in five classes and Super five twisted-pair is defined as 4, Gigabit Ethernet is required to use all 4 pairs of lines for communication.