Ethernet over twisted pair technologies use twisted-pair cables for the physical layer of an Ethernet computer network.Early Ethernet cabling had generally been based on various grades of coaxial cable, but in 1984, StarLAN showed the potential of simple unshielded twisted pair by using Cat3 cable—the same simple cable used for telephone systems. This led to the development of 10BASE-T and its successors 100BASE-TX and 1000BASE-T, supporting speeds of 10, 100 and 1000 Mbit/s respectively. Often the higher-speed implementations support the lower-speed standards making it possible to mix different generations of equipment; with the inclusive capability designated 10/100 or 10/100/1000 for connections that support such combinations. All these three standards support both full-duplex and half-duplex communication.The higher speed 10GBASE-T running at 10 Gbit/s, is different in that it defines only full duplex point-to-point links which are generally connected by network switches, and doesn't support the traditional shared-medium CSMA/CD operation.All these standards use 8P8C connectors,[note 1] and the cables from Cat3 to Cat7 have four pairs of wires; though 10BASE-T and 100BASE-TX only require two of the pairs.A 40GBASE-T standard, transporting 40 Gbit/s over up to 30 m Cat.8 cable is being defined as P802.3bq.