'T-1 is made up of 24 digital channels. This requires a digital connection device (CSU/DSU {customer switching unit/digital switching unit}) to connect to four wires to carry the information. All T1 lines require that a Channel Service Unit (CSU) be connected between your Data Terminal Equipment (DTE), i.e., a personal computer, and the T-1 line. A CSU serves both as a surge protector (to protect your equipment from voltage anomalies such as lightning) and a monitor of the line itself.

As mentioned previously a T1 connection is capable of delivering 1.5Mbps. DSL connections are also capable of delivering this speed however they are not nearly as reliable as a T1 connections and should not be considered as a business connections unless it's SDSL and even then you will likely have some downtime. If you have critical information being hosted in your office or have a large number of users accessing the internet on a regular basis, consider getting a T1 connections. Also remember to get a professional's assistance when you search for your provider. Each company will tell you their connection is the best available but a broker will act as your agent and help you find what's right for you.