| Many telecommunications service providers are | | | | a total of 24 channels, which can be allocated to use |
| offering T1 PRI to businesses in order to provide fast, | | | | as separate voice lines, or bandwidth. A full line that is |
| reliable voice and data service, but what exactly is this | | | | completely dedicated to bandwidth can provide up 1.54 |
| service? | | | | Mbps of bandwidth. |
| PRI refers to Primary Rate Interface, which is a | | | | T1 lines provide dedicated bandwidth, allowing for |
| telecommunications standard that allows several voice | | | | uninterrupted network and Internet service which in turn |
| and data transmissions to be sent and received | | | | provides the most reliable connection commercially |
| through a single copper or fiber-optic cable. | | | | available. Basically, a T1 PRI data and voice line is |
| The Integrated Services Digital Network (ISDN) | | | | leased by a business or individual, allowing them to |
| typically provides two levels of service. The first is | | | | receive service over a reserved line. This is much |
| most commonly known as Basic Rate Interface (BRI). | | | | more reliable than traditional "switching" methods, |
| Most types of BRI are intended for residential, small | | | | because it means that the bandwidth that has been |
| business, and other light-load situations. The Primary | | | | leased will always be available to the leasee. |
| Rate Interface (PRI) is more commonly reserved for | | | | Many telecommunications providers are offering |
| larger users requiring more extensive needs. | | | | services to their residential and commercial customers. |
| Both of these services include several B-channels and | | | | Some of these service providers, such as Cavalier |
| one D-channel. Each B-channel carries data, voice, and | | | | Telephone T1 PRI, are available in full or "fractional" |
| other services to the user, while the D-channel carries | | | | lines. Fractional makes it possible to lease only a partial |
| the control information. Each of these B-channels is | | | | T1 line, such as 12 of 24 channels, which can be |
| capable of delivering one voice line or 64 kbps of | | | | offered at lower prices than full lines. However, these |
| bandwidth. The BRI provides two B-channels, while the | | | | fractional lines are becoming less popular due to the |
| Primary Rate Interface, or PRI, consists of 23 | | | | steady decrease of T1 PRI prices. As the price of a |
| B-channels. | | | | full line continues to drop, fractional lines are not as |
| In North America, most PRI services are made | | | | cost effective as they were in the past. |
| available through the use of T1 lines. A line consists of | | | | |