What is PRI/T1?

You are reading a page, where you will be given information on PRI/T1 or Primary Rate Interface via a T1 line. If you are interested in the future's telecommunications services and how your office could use it, with a high capacity digital circuit, I suggest that you should read on.

As shown in Figure 1, PRI/T1 is an end-to-end digital circuit in the Integrated Services Digital Network (ISDN, the set of international standards which defines the access to all-digital, advanced networks). It transmits data, voice or video coming from the ISDN Network to the server of Ozeki Phone System XE. Then this connection is transformed into either one or several Voice over Internet Protocol (VoIP, a protocol, which directs voice transmission via the Internet) phone lines or provides internet connection to one or several computers.

what is pri t1
Figure 1 - What is PRI/T1?

It is a great solution for larger organisations that require many analog lines to obtain a PRI/T1 line instead of separate additional analog trunks since they would have to buy separate analog trunk cards to terminate all those lines in their Public Branch eXchange (PBX, which connects all the calls whether from inside or ourside a local network to the appropriate extension) for separate rental for each line, probably wasting the free call capacity of certain individual lines.

PRI/T1 has 23 B-Channels (bearer channels), which carry data voice and other services and one D-channel (data channel), which signals and controls information.So you can have as high as 1544 Mbps service in the United States, Japan, and Canada. A PBX and a central office of a telephone company or a long distance company are connected by it.

Data is transmitted at 64 Kbps on each channel. Both analog and IP PBX systems can be reached by it, although a PRI Card might be needed to terminate the PRI circuit on the pbx. Two PBX systems can also be connected by it, providing up to 24 channels between them.

Why should you get PRI/T1 instead of separate analog trunk lines?

  • No wait for an Auto-Attendant is needed, the desired extension is directly connected.
  • All extensions have an own caller ID.
  • Calls would be distributed more evenly than they would be on separate analog lines.
  • Calls are established faster via PRI/T1.
  • The voice is clearer on digital lines.
  • PRI/T1 connections are more reliable and more private, and it is harder to tap into them to listen to conversations.
  • Video conferences can be held at the same time a fax or any other data or voice in sent via various channels.

Large organisations can use a digital line called a PRI/ T1 in North America and Japan. Each PRI / T1 line can carry up to 24 channels of voice communications simultaneously by using multiplexing/ de-multiplexing techniques.

The customer needs to procure a PRI / T1 Card, to terminate the PRI/ T1 line in their PBX. Then only one line would be coming into your organization but thirty people could simultaneously have conversations through it. And it would only need a single rental package from the local telephone company.

The server of Ozeki Phone System is connected to the ISDN network via PRI/T1. So it does not matter where you live and which standards you use, as the multifunctionality of the Ozeki Phone System solves the problem created by them, giving you the best service possible.

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