Trunk Line Two. Very high speed digital transmission line offering a total data-carrying capacity (bandwidth) of 6.312 million bits per second (Mbps) with 96 individual channels in the US and Japanese (J-2) versions, and 8.444 Mbps with 120 channels in the European (E-2) version. T-2 and its variants are medium-independent and can run on ordinary (unshielded twisted pair) telephone lines, coaxial and fiber-optics cable, and radio (microwave) media.