T1 (T-1):

A leased-line connection to the Internet which can transfer data at 1.544 Mbps. A T-1 line could transfer a megabyte in less than 10 seconds if at maximum theoretical capacity. A T-1 line contains 24 individual channels, each of which can transfer data at 64 Kbps. Each of these 24 channels can transfer voice or data traffic. Many telephone companies will allow you to buy a portion of these individual channels, called "fractional T-1 access". T1 lines are also called DS1 lines.