When trying to make the decision between a T3 line and a T4 line, the main considerations are how much bandwidth you need and how much money you have to spend on the line. The second question may be easy to answer, but the first one can be much more difficult. T3 and T4 lines require fiber-optics, whereas a T1 line is carried over normal copper lines. This makes T3 and T4 lines easier to install since it is easier to install one fiber-optic line than three or four copper lines. T3 lines are still widely used by many medium-sized businesses, as are T1 lines. The T3 and T1 are the most widely used.
