What is a T1 and PRI?

Most of us are familiar with a normal business or residential lines from the phone company. A normal phone line is delivered on a pair of copper wires that can transmit voice signals or data signals.

The phone company moves phone service on nearly all digital signals rather than analog signals. Your analog line gets converted to a digital signal. Nearly all digital data currently flows over fiber optic lines, and the phone company uses different bandwidth designations to talk about the capacity of a fiber optic line.

If your office has a T1, PRI line, or isdn pri, it means that the phone company has brought copper or a fiber optic line into your facility. A T1 line has 24 digitized voice channels, and can carry data at a rate of 1.544 megabits per second. The T1 or PRI line can be broken up for voice and data. The voice goes into the PBX equipment while the data goes into a router.

An isdn t1 line can carry about 192,000 bytes per second -- roughly 60 times more data than a normal residential modem. It is also extremely reliable -- much more reliable than an analog modem. Also, a T1 is asynchronous, which means it transmits data and voice at the same speeds while uploading or downloading. When companies use DSL technology or Cable internet technologies, they lose this service level. Depending on how a T1 is configured, it can typically handle quite a few people. For general internet browsing, hundreds of users are easily able to share a T1 line with no noticable slowdown. If they are all downloading music files or video files simultaneously it may become a problem, but heavy downloading isn't typically a common issue.

A T1 line cost depends on who provides it and where it goes. Nuvox offers some of the most competitive rates in the business. To request a quote, click here.

A large company may need something more than a T1 line. Perhaps a t3 or more depending on bandwidth needs. Nuvox is capable of suppling all your phone service needs and data network requirements. The following table shows some of the common line designations and their capacities:

DS0 - 64 kilobits per second
ISDN - Two DS0 lines plus signaling (16 kilobits per second), or 144 kilobits per second
T1 - 1.544 megabits per second (24 DS0 lines)
T3 - 43.232 megabits per second (28 T1s)
OC3 - 155 megabits per second (100 T1s)
OC12 - 622 megabits per second (4 OC3s)
OC48 - 2.5 gigabits per seconds (4 OC12s)
OC192 - 9.6 gigabits per second (4 OC48s)

To find out what is right for you, Contact Me.

A PRI line is a t1 service, with a configuration for voice lines that includes Direct Inward Dial (DID's) numbers. Nuvox also offers a unique, robust, intuitive PRI service called VoxIP. This service allows you to dynamically allocate both voice and data channels to adjust depending on usage. To learn more about this product, click VoxIP.