How A T1 Line Works

A T1 is a digital transmission line that carries voice or data. Normal business or residential phone lines are copper wires that are used to transmit voice (or data) as an analog signal. A T1 uses digital rather than analog signaling making for much faster transmission. Since most central office equipment is now digital, analog connections are first converted to digital before being sent.

A T1 consists of 24 channels. These channels are not static and can carry conversations or data as needed. It can carry data at a rate of 1.544 megabits per second. A T1 that is used for voice can plug into the phone system while a T1 used for data can plug into the network router. T1s can also be split so that part of the channels can be used for voice and part for data. This is particularly helpful for smaller business applications. Each T1 can handle 24 simultaneous conversations. (Or 23 based on configuration).

A T1 line rates can carry about 192,000 bytes per second. This figure is more than 50 times faster than a standard modem. The bandwidth on a T1 makes it possible to have multiple applications; run large data files and perform other tasks such as video conferencing. A T1 will also be able to handle future applications that require this type of speed.

T1 technology is also quite reliable. Failures are not common and when they do occur, outages are typically not lengthy. Depending on your business telephone equipment you may be able to route traffic over another method during an outage or during times when the T1 is full. The T1 may be terminated on a smart jack in the telephone room where it can easily be extended into the phone system or network for use.

You may opt to use a CSU (customer service unit) with your T1. The CSU acts as a termination point for the T1 and provides a test position so that it can be checked if there are problems. A CSU is a good option and is required in some areas. Many times problems with a T1 can be resolved remotely. Be sure to check with your vendor for specific service plan options and include the times that your business and service center are operational.

The cost of T1s has been dropping since most central office equipment is now converted to digital technology. Typical costs range from $1,000 to $1,500 per month and you may be able to find lower pricing. A single T1 with moderate usage could handle about 100 employees.

Phone intensive businesses would require more than that. In data applications hundreds of users can share a T1 if used for general browsing. To help determine your specific needs you can get current phone usage information from your vendor. Allow for approximately 10% growth or more if your business warrants it.

A T1 will provide clear, crisp service that will provide a good image for your company. If your business is large you may require more than one T1. T1s come in larger circuit amounts to accommodate any size business. A T3 is equivalent to 3 T1 lines. T1 lines are engineered for your company based on distance to the central office and facilities. You can look forward to a savings of hundreds or thousands of dollars per year.