What Is the Difference Between a T1 and a T5 Line?

By Andrew Meer

The general idea behind both T1 and T5 lines is to provide high-speed and reliable Internet access. T1 lines have been used for over a decade, mainly by businesses requiring critical connections to the Internet. T5 lines are newer and mostly still in development as of 2010. However, it is expected T5 lines will surpass T1 lines in terms of reliability and speed.


T1 lines use a special type of telephone to transfer data with the service provider. The telephones lines are made out of twisted copper or with bundled glass fibers, which are more commonly known as fiber optics. T5 lines use coaxial cables to transfer data, a type of electrical cable first developed to be a part of AT&T’s L-carrier system. The technology was later upgraded to be used with T5 lines.


There are two types of T1 lines available, which are known as full T1 lines and fractional T1 lines. Full T1 lines, which provide speeds of up to 1.5 megabits per second, are much faster when compared to a fractional T1 line’s 128 to 768 kilobits per second. T5 lines are over 250 times faster than a full T1 line, with a maximum transmission speed of 400.352 megabits per second.


T1 lines were first made by AT&T Bell Labs for Japan and the United States. As of 2010, thousands of companies lease T1 lines across the United States. Even though the technology behind T5 lines existed even in the 1980s, most of its features are still in various stages of development. Therefore, it is rare to find a telecommunications company providing T5 lines.


T1 lines are expensive to use, mainly due to the high monthly subscription costs. A full T1 line can cost as much as $1,000 per month, and even a fractional T1 line can cost about $800 per month, as of 2010. Because T5 lines are fairly new, there is no proper pricing structure available. However, the price of a T5 line can be significantly higher than that of a T1 line.


T1 lines are a fast and reliable way to transfer data, because they are not affected by factors such as distance from the service provider, weather conditions and fluctuations in network traffic. However, the reliability of T5 lines is largely unknown because the technology is not widely used. T5 lines when fully developed will most likely be available to large companies, mainly due to the high costs that are sure to be associated when purchasing them.