T1 Fractional And Full
T1 Lines have been the primary source of mission critical bandwidth for companies of all sizes for about twenty years. With so much history, a basic understanding of the T1 line should be common knowledge among business owners who are looking for reliable bandwidth for Internet access, data communications, or multiple telephone lines. Even today most small business owners and managers still do not know how a standard T1 line works or what it is capable of providing.
One type of T1 connection is called a Fractional T1 line. This t1 line typically describes an Internet circuit that uses a piece or a fraction of a Full T1. Fractional T1's are used for telephone lines or even integrated T1s, but less often then for Internet access. A Fractional T1 might be sold in nearly any fraction of a 24 channel, 1.54Mbps circuit. For example, out of the 24 channels in a Full T1 line, 12 channels could be used in a Fractional T1 to provide a 768k connection, which is half of 1.54Mbps. Other Fractional sizes include 1.1Mbps, 512k, 384k, 256, 128k, and even 64k, although the smaller sizes are very uncommon. As T1 Providers have become more competitive, prices on Full T1s have come down so much that Fractional T1s have become less cost effective. For example, a Fractional T1 of 768k carries only half of the bandwidth of a Full T1, but usually saves only 5% to 15% of the price of a Full T1. This does not make much sense in applications where only one or two T1 lines are needed, unless the budget is extremely tight. However, this can add up to significant savings when using hundreds of T1's across a large company's multi-location VPN or frame relay network.
Full T1 Line is a term typically used to describe a circuit that provides 1.5 megabits per second of high speed Internet access, which is the most common type of T1. A Full T1 can also be used to carry telephone lines and/or VoIP calls, both of which are covered within the "Voice, PRI" and Voice Over IP sections here. Nearly all office-based and modern retail businesses require some type of Internet access in order to perform their daily operations, and many have mission critical Internet needs that allow them to continue business operations at all. There are many choices to fulfill this need for Internet access, including Dial-up connections, ISDN, DSL, Cable, Wireless applications, a T1 Line, or something larger like a DS3 or OC-3.
A T1 Line consists of 24 channels that transmit data at 64Kbps each, therefore giving a Full T1 Line the capacity to transmit 1.54Mbps of data synchronously. Using today's standard email applications and common Internet searching, this amount of bandwidth could support anywhere from one to approximately 75 users depending on their needs, preferences, and the company's budget. Most commonly, Full T1 Lines are used in offices with 5 to 50 employees. A T1 circuit provides the most reliable bandwidth available when leased from a high quality T1 Provider, which is why businesses are willing to pay more for a T1 than for other services like DSL or Cable. In some applications, a T1 can save money for a company who uses a less reliable bandwidth connection. Since multiple services might be combined on a single T1, cost efficient solutions are often available if you know what service to ask for and which providers offer those services in your area.
Internet T1 pricing starts at approximately $400 per month, but can cost more than $1000 per month if the location of the installation requires a long loop to connect to the network of your local phone company to the network of the T1 provider. This is usually only the case in very small towns or rural areas where facilities are less dense.
