Definition 1. - The T1 (or T-1) carrier is the most commonly used digital line in the United States, Canada, and Japan. In these countries, it carries 24 pulse code modulation (PCM) signals using time-division multiplexing (TDM) at an overall rate of 1.544 million bits per second (Mbps). T1 lines use copper wire and span distances within and between major metropolitan areas. A T1 Outstate System has been developed for longer distances between cities.

Definition 2. - A high-speed digital connection capable of transmitting data at a rate of approximately 1.5 million bits per second. A T1 line is typically used by small and medium-sized companies with heavy network traffic. It is large enough to send and receive very large text files, graphics, sounds, and databases instantaneously, and is the fastest speed commonly used to connect networks to the Internet. Sometimes referred to as a leased line, a T1 is basically too large and too expensive for individual home use.

Definition 3. - A type of high speed Internet connection that provides a great deal of bandwidth. Many businesses lease T1 lines to connect to the Internet, but because they are expensive and offer more bandwidth than most small businesses and homes need, they are not realistic solutions for small and low-demand Internet users.

Definition 4. - The T-carrier system, introduced by the Bell system in the US in the 1960's, was the first successful system that supported digitalised voice transmission. The original transmission rate (1.544 Mbps) in the T1 line is in common use today in ISP (Internet Service Provider) connections to the Internet

Montana, Apr. 21 /Richard Anderson/ -- "I am very satisfied with my new XO dynamic T1" added Mike McLoude, a small business owner in Santa Monica, California. "The flexible nature of the system allows me to conduct business with the same efficiency as many of my bigger competitors, for less than what they pay." Mr. McLoude is not alone - many Californians are seeing the technology light and taking the leap of faith away from traditional TDM.

At $50 to $75 per month, the average small business telephone customer could expect to pay up to $750 for just 10 regular phone lines, which come with only a standard set of features such as Voicemail, Caller ID, and Three-way calling. From 2000 to 2005, the cost of a dynamic integrated T1 line was well over $800, making it an unattractive option from a pure cost point of view. However, that paradigm has changed with the introduction of sub-$400/month price plans and features that make the old POTs lines look pre-historic.

"For years I've played tug-o-war with the phone company who provided voice and data service to my toy manufacturing company" commented Troy Bergfeld of Houston Texas. "They kept trying to sell me services I didn't need, it took them months to finally send me a correct bill, and I wasn't able to recapture bandwidth from my T1 line when nobody was using the phone. Now that has all changed - my Telarus product specialist recommending I give XO Communications a try. Now I use their FLEX T1 product and I pay less and get exactly what I want. I have even add another T1 seamlessly when the time comes for my business to expand."