There are many articles on Benefits of PRI Lines on Internet, But this article will help you understand the whole technology from a layman’s point of view. How can PRI lines benefit your business? Recently there have been changes in the market now PRI over SIP is also provided by PRI providers like TATA and BSNL, which is a very good sigh.

Basically there two types of Land Lines available in Market, One is our age-old PSTN line (which is generally termed as Land Line). The other land-line is PRI line, which is Digital.

PRI connection seems to be costlier @ first glance, however, if we understand the benefits correctly – we will realise that we can save lots of money.

What are PRI Lines?

PRI is a digital telephone connection which is based on IP rather than our conventional analogue telephone lines.The biggest difference is that it has 30 Channels, which means that 30 people can talk simultaneously. Also, it provides 100 Individual Numbers.


  1. PSTN – Public Switched Telephone Network – which in other words is our normal phone Land lines which we get from BSNL/MTNL.
  2. PRI -Primary Rate Interface – don’t go by the Jargon, in simple words its a digital connection – which gives you 30 simultaneous telephone conversations.
    1. Of course, PRI can be used for lots of other things – but to make things simple, we will stick to this definition.

Mathematics of PRI Lines

  • PRI Line is basically 2 Mbps line which works with two modems on both the sides.
  • Every Digital Audio Channel requires 64 kbps.
  • Now if we divide 2 Mbps (2048 Kbps) by 64, we get 32.
  • Out of these 32, two are control channel and 30 are Communications (or Audio) Channels.
  • That is the reason PRI in India supports 30 Calls simultaneously.

Advantages of PRI :

  1. PRI has Crystal Clear – digital voice.
    1. Everything in PRI connection – all the equipment, cables, protocols  – everything is digital – nothing is analogue.
    2. As a result – you get a crystal clear voice – which is un-imaginable in case of normal PSTN lines.
    3. Why? In case of PSTN lines, there is a conversion from digital to analogue @ more than 2 points – when one call is established. – This conversion leads to lots of disturbances.
  2. PRI lines have fast call connection
    1. You will be surely surprised when you use the PRI for the first time, it is amazingly fast.
  3. Pooling of bill for all 30 PRI lines
    1. If you have 10 PSTN lines, with same or different calling plans – you will have to manually decide which number to make calls from.
    2. It may happen that for first 3 numbers – you make lots of outward calls – and end up getting huge bill.
    3. Whereas for other numbers – you don’t even use the free calls.
    4. Now, with PRI – this is automatically solved – all the calls from all the 30 lines are pooled together – when you are being billed.
  4. Automatic Call Distribution
    1. With these 30 lines, you get 100 numbers – which means they are your hunting lines – if one line is busy the call can land on next line – your customer never gets a busy tone. – GREAT feature
  5. DID – Direct Inward Calling.
    1. You can publish various telephone numbers for different people/department in your company.
    2. Example – 0260-6612900 is supposed to reach Enjay Sales Desk, 0260-6612950 will reach Support Desk directly.
    3. This feature is built in into PRI technology, for normal PSTN lines, this is not available – it has to be done through an expensive EPBX box.
  6. DOD – Direct Outward Dialling
    1. Many times it happens that you receive a call from some company, and you are not able to pick up the call.
    2. Now when you call back – the call lands to the receptionist – she has no idea who made the call.
    3. This happens because a normal EPBX – makes outward calls thru any available telephone line.
    4. With PRI – this problem is solved – the call is always made outside using the users DID number – which means that the person being called – if calls back – the call will land exactly to the person who had originally called.
  7. Easily expandable
    1. PRI line is actually a 2 Mbps line, which utilises 64 Kbps for each call. This is also called E1 line – which has 32 channels of 64 Kbps – out of which 2 are for control and rest 30 are used for communication.
    2. So, the number of PRI lines can be increased on a very short notice.

Enjay Synapse supports PRI Lines and other types


  1. Gaurav

    Thanks buddy.., perfectly explained.

  2. Bhanu

    Dear Sir,

    Kindly confirm that PRI is working if ciruit is configured on Framed .?

  3. Pragnesh Shah

    Good effort to serve products & technology knowledge to industry with product promotion.
    Keep it up.

  4. Harbans Lal

    Sir, if I wish to use some channel or all the 30 channels for pco. Is it possible to get ‘Bill displayed’ on every booth for individuals.????

  5. Impressive CRM

    Nice Efforts, to add it – what if you can provide the comparison in a tabular format. Also highlight the minuses (if any).

  6. Sunil nevagi

    Hi we want to start our own virtual telephony service for our 600 plus clients .
    Pl advise how u can help us .

  7. Syed Ahmed

    Looking for PRI Lines, CRM and Zendesk for the complaints about the start company

  8. Maira Prohonic

    Terrific article! This is the type of info that should be shared across the internet. Disgrace on Google for now not positioning this submit upper! Come on over and consult with my web site . Thank you =)|

  9. Nilsa Bewick

    Heya i’m for the first time here. I came across this board and I in finding It really useful & it helped me out a lot. I’m hoping to give one thing again and help others such as you helped me.|

  10. Jomwins

    I needed to thank you for this good read!! I definitely enjoyed every little bit of it.
    I have got you bookmarked to check out new things you post…

Leave a Reply

Your email address will not be published. Required fields are marked *

You may use these HTML tags and attributes: <a href="" title=""> <abbr title=""> <acronym title=""> <b> <blockquote cite=""> <cite> <code> <del datetime=""> <em> <i> <q cite=""> <s> <strike> <strong>