| Basically, T1 is a leased line used in | | | | How do T1 lines work? |
| telecommunications. By "leased", it is meant that | | | | T1 service is typically provided over a network of |
| the company using the T1 line is paying to rent | | | | copper or fiber-optic cables. Every complete T1 |
| the line, in essence reserving it for their own | | | | line consists of 24 channels that transmit data, |
| bandwidth needs. This allows the user to maintain | | | | independently, at 64Kbps. These complete T1 lines |
| a single open circuit at all times, as opposed to | | | | are referred to as "full T1," and provide a total of |
| traditional telephone services that use the same | | | | 1.54 Mbps of data synchronously (both incoming |
| line for several connections through a process | | | | and outgoing). |
| referred to as "switching." | | | | If used for telephone lines, one full line will provide |
| The T1 line uses reserved circuits which operate | | | | 24 separate phone lines. This is useful for |
| over copper or fiber-optic cables. These leased | | | | businesses or call centers which receive many |
| lines guarantee the user necessary bandwidth for | | | | telephone calls, as one full T1 line is much more |
| network traffic, making them ideal for businesses | | | | cost-effective than paying for 24 separate phone |
| which may rely on these needs. T1 lines are also | | | | lines. |
| commonly used by businesses and other | | | | It is also possible to lease a portion of T1 line, |
| organizations to connect geographically separated | | | | called "fractional T1". These lines offer a lower |
| locations for private voice and data networking, | | | | data transfer rate at lower cost, and are |
| and are typically rented at a monthly or yearly | | | | commonly used in hotels, apartment buildings, etc. |
| rate. | | | | to provide Internet access to residential |
| AT&T first introduced T1 technology in the | | | | customers. Since each T1 line contains 24 |
| early 1960's, but it was not until the early 1990's | | | | channels, it is possible to purchase any number of |
| that the market for T1 service became | | | | these channels. For example, 12 channels will |
| competitive enough to allow the service to | | | | provide you with a 768Kbps connection (12 |
| become affordable for normal consumer and | | | | channels x 64 Kbps). |
| business use. Many top companies, such as IBM, | | | | The separate channels can also be allocated to |
| and even the United States Government have | | | | provide separate services. For example, a full T1 |
| been using T1 for quite some time, due to its | | | | line can be used to provide 12 separate phone |
| reliability and performance. | | | | lines, as well as 768Kbps of bandwidth. |