A T1 connection is the most popular method for Internet access among businesses. T1 service is fast and reliable - most providers can guarantee 99.99% uptime - and features increased security. Like DSL, T1 connections are "always on," meaning that as long as your computer is turned on, you will be connected to the Internet.

T1 service is symmetrical connection, allowing for downloads and uploads of up to 1.5 Mbps, which is about 30 times as fast as dial-up. The quality of a T1 line is much better than analog phone lines, which translates into a clearer signal and faster connections to websites and quicker downloads.

Since T1 service lines are dedicated, you will always have access to the full amount of bandwidth you are entitled to. However the actual performance you experience at an individual level will drop depending on how many users are online at that time. A single T1 connection can support dozens to hundreds of users, but the speed and efficiency will drop as more people use it simultaneously.

Levels of T1 service
There are multiple flavors of T1 lines. At its most basic, a T1 line can be used to handle either your voice or data needs.

An integrated T1 line provides voice and data on the same digital circuit. With this service, you can decide how many of the T1 connection's 24 channels will be reserved for voice calls, and what's left is used for data.

You can also purchase a fractional T1 line, which provides only a portion of the total bandwidth. However, with prices of T1s as low as they have ever been, many companies are selecting full T1s because the price difference is almost negligible.

Another option to consider is burstable T1 - a type of "pay as you go" service where you pay for a specific amount of bandwidth you intend to use. If you exceed that amount, you can still tap into the ISP's total available bandwidth and pay a premium above your standard rates. Think of it as going over your allotted minutes on your cell phone plan. Pricing can be very expensive but could be worthwhile for companies that know their data traffic patterns and have highly seasonal activity. Consider investing in a full T1 - or multiple T1s - before looking into burstable options.

For even better speed and performance, ISPs offer bonded T1 lines. Bonded T1s allow you to use the full bandwidth of multiple T1 lines at once. For example, two bonded T1 lines can provide up to 3 Mbps of data transfer in a single connection. By combining the speeds of individual T1s into a single pipeline, you allow for more bandwidth than two separate T1 lines.

Downside of T1 service
The most obvious drawback of T1 service is the cost. You will pay far more for T1 access to the Internet than for DSL. In fact, actual connection speeds of T1 and DSL are very similar. However, T1 provides a much more reliable connection and you are paying for that guaranteed uptime. For businesses that rely heavily on employee and customer access to data and applications, T1 is likely the best option.