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T1 lines can transfer data at a speed of 1.544 megabits per second. Explore additional ways to connect with internet connection visuals.
Scott J. Ferrell/Congressional Quarterly/Getty ImagesWe’re all familiar with the standard business or residential phone lines provided by the telephone company. These typical phone lines use a pair of copper wires to transmit your voice as an analog signal. When a regular modem is connected to these lines, it can transfer data at around 30 kilobits per second (30,000 bits per second).
The telephone company now sends most voice communications as digital signals rather than analog. Your analog phone line is converted into a digital signal by sampling it 8,000 times per second with an 8-bit resolution (64,000 bits per second). Today, the majority of digital data is transmitted through fiber optic lines, and the phone company uses different terms to describe the capacity of these fiber optic lines.
If your office has a T1 line, it means the phone company has provided a fiber optic connection to your office (though it could also be delivered over copper wires). A T1 line can transmit 24 digitized voice channels or provide data at a speed of 1.544 megabits per second. If the line is used for phone calls, it connects to the office phone system. If it’s used for data, it connects to the network’s router.
A T1 line is capable of handling approximately 192,000 bytes per second — that’s about 60 times more data than a standard residential modem. It is also very dependable, much more so than an analog modem. Depending on the usage, a T1 line can support a large number of users. For general web browsing, hundreds of users can comfortably share a T1 line. However, if everyone were downloading MP3 files or video files at once, it could become an issue, although this is still a rare occurrence.
A T1 line typically costs between $1,000 and $1,500 per month, depending on the service provider and its location. The other end of the T1 line must connect to a web server, and the total cost is a combination of the charges from the phone company and the ISP.
For larger companies, a T1 line may not be sufficient. Here’s a list of some commonly used line designations:
- DS0 - 64 kilobits per second
- ISDN - Two DS0 lines with signaling (16 kilobytes per second), or 128 kilobits per second
- T1 - 1.544 megabits per second (24 DS0 lines)
- T3 - 43.232 megabits per second (28 T1s)
- OC3 - 155 megabits per second (84 T1s)
- OC12 - 622 megabits per second (4 OC3s)
- OC48 - 2.5 gigabits per second (4 OC12s)
- OC192 - 9.6 gigabits per second (4 OC48s)
