Which T1 services will serve your business best?
Full T1 Service
A full T1 service is usually sold as a complete circuit of up to 1.544Mbps total speed. This communications channel is often referred to as a digital trunk line. A T1 is a dedicated circuit from the telecommunications provider to the customer and is not shared with any other customers. This is why it is often referred to as a ‘dedicated’ line. The full circuit can be either data or voice, but not both.
Burstable T1 Service
This is a full T1, sold with some sort of measuring technology attached at the ISP’s end. You purchase an amount of bandwidth that you receive each month and pay a premium when your T1 exceeds this level of data.
A channelized T1 contains 24 individual channels, each capable of carrying voice or data. The full set of channels has the same speed as a full T1, but the individual channels may be split into voice lines or data lines using a device called a Channel Service Unit/Data Service Unit or CSU/DSU. The CSU/DSU is used to split off the voice channels from the data channels, allowing the voice channels to be connected to a phone system or PBX. The data lines are then connected to a router serial interface and often are used to provide Internet connectivity.
A fractional T1 is one or more channels bundled together and sold to a customer as a set. This allows a consumer to purchase less than a full T1′s bandwidth at a lower cost. The price of T1′s has fallen significantly however and fractional T1 service is becoming ever more rare. Like the channelized T1, individual channels can be voice or data and a CSU/DSU is used to split the channels, however less than the full set of 24 channels is available to the customer for use.