Primary Rate Interface - an Overview

There are two basic types of services, provided in ISDN system. The first one is Basic Rate Interface (BRI) which is installed at home or any small business organization. The other is known as Primary Rate Interface or PRI line which is applicable for large business houses that have their own telephone exchange system. With the growth of business, it is inevitable that you have to be technologically advanced. Therefore, PRI system is the only thing you need to grow and establish yourself as the leading company of your sector. Here, you will get a thorough overview about PRI line and its benefits and limitations.

What is PRI Line?

• In a nutshell, a PRI system is an end-to-end digital circuit which enables the delivery of 30 calls simultaneously.
• There are number of D-channels and B-channels which are responsible for data transfer, video conferencing, voice calling along with other controlling and signaling information.
• To be specific, a PRI line consists of 23 Kbps B-channels and 64 Kbps D-channels.
• It also uses a T-1line where the D-channel is one and the 30 Kbps B-channel uses an E1 line.
• Are you planning to get access PRI on T-1 line? Then you will get internet speed up to 1.544 Mbps and it carries 23-24 channels through two pairs of copper lines. It is popular in USA.
• Besides, any E1 line user get more speed where 30 channels are carried simultaneously and it is popular in India and European countries.
• PRI uses Q.931 protocol over D-channel.

Benefits of PRI

1. No more going through the PBX auto-attendant. As the service provider of the PRI system provides around nearly 500 numbers for each extension, any outsider can call the extension directly.
2. The caller ID is another vital benefit. Every extension has its own number and that is shown while they are calling to.
3. Call hunting is easy now. But, if you still have analog trunks, you have to consult with the service provider and also need to pay additional cost for that.
4. Voice and data access is now possible with PRI system. There are some service providers who often provide data transmission at free of cost for a certain period of time.
5. In comparison to analog trunks, PRI are always better as it is an end-to-end digital line. Thus, it is also more reliable and easy to maintain.
6. Phone tapping is no longer an issue of tension as it is difficult to tap digital lines.
7. This is a multifunctional line which provides data connectivity, faxing, video conferencing, etc. and all these are done simultaneously.

Limitations of PRI Line

1. If you have to make long distance or international calls, PRI is not that much cost-effective. You should go for SIP trunks.
2. To connect PBX or EPABX through a single PRI line still costs high.
3. With PRI system, the Inter Branch Communication doesn’t come at free of cost

Hopefully you have got an idea about PRI system and its advantages and disadvantages. Are you thinking of growing your business? Go for installing this.