What is the primary rate interface?

The primary rate interface is the level of enterprise telecommunications services of the Integrated Services Digital Network (ISDN). Also known for the abbreviation PR, it uses the circuits of T-Nosiče (T1) or e-Carrier (E1) phones. Each four -wire circuit T1 provides 24 digital data channels, while each E1 contains 32 channels. Many large offices and call centers Pro provide voice and data services to their employees. Internet service providers also use it to connect their modern banks with a telephone network.

Before voice internet via the Internet (VoIP) became widely available, at usually the best phone solution for large corporations. The full use of the T1/E1 lines caused the primary rate to be more cost -effective than the use of the same number of standard telephone lines. ISDN also provided a two -channel interface of basic rates (BRI) for domestic and small businesses. Once the Cable Internet and Digital Subscriber (DSL) service has been captured (DSL)With a higher width width, bri was effectively abandoned.

In North America and Japan, the primary rate interface is provided via T1 lines in the telephone network. Each T1 contains 23 data channels at 64 kilobite per second (KBPS), also known as the wearer channels (B). Each can carry one "conversation" of voice or date at a time. The T1 line also contains one delta (D) channel, which is used for signaling and checking the other 23 channels.

Europe, Australia and most of the rest of the world implement primary rates interface through E1 network lines. E1 includes a synchronization channel that T1 does not have, as well as 30 B channels and one D channel. E1 operates a faster speed of 2.048 megabits per second (MBPS) compared to 1.544 Mbps T1. However, the channel data rate B for E1 and T1 is still 64 kbps.

Lines T1 or E1 Groups can be combined to PoLarge primary rate of nterface connection. For example, two E1 lines can be paired and provides 60 B channels and two D channels at 64 kbps. The second D channel in this case would be used as a backup than as an active control channel. Two channels D are usually needed even if more than two lines T1 or E1 are combined.

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T1 or E1 lines can also be combined into a high-speed (H) channel for primary speed, also known as Multi-Orate ISDN. It is a collection of B channels connected together to support applications that require data speed faster than 64 kbps. For example, a video or high quality audio transmission may require a much larger bandwidth than the PR.