ISDN PRI: We’ve Heard Of That, Run That By Us Again

PRI, T1 and ISDN PRI Business Internet and Phone Services

Below is a diagram, followed by a simple explanation of how ISDN PRI telephone lines work, ending with a cost savings layout. We hope to help you understand what this technology can do for your business. References from anywhere in the world are always available, please ask! Call us or click ‘Request a Quote’ to the right to aquire a quote from anywhere in the world at the lowest price, guaranteed! We can deliver ISDN PRI’s, T1’s, SIP trunks, VoIP, Fiber, DS3’s and OC-x circuits. Get an idea of how much we can seriously save your business today!


What is the difference between phone services?!

First, imagine a highway. This highway represents the type of phone line coming into your business. The highway could be either:

  1. An Analog Highway
  2. A Digital Highway (ISDN PRI)
  3. Voice over IP Highway

Now, the lanes on this highway represent potential pathways in which a call can be made, or received. The number of lanes are directly related to the type of phone line, or highway in which our voice travels. We need some cars!

Lastly we have cars on the highway, and they are your phone number(s).

By using analog phone lines, you are limiting your car to only one lane. There is no changing lanes and travel is inefficient. If you want to make or receive a call on that same number, then your cars have to be able to dump their cargo onto additional cars that aren’t being used. This is a feature called “roll over” lines. If the main number is in use, the call gets rolled over into a lane that isn’t being used.

It boils down to price. With an analog phone line solution, you need to pay for as many lines as you hope will be enough for your customers to never get a busy signal. Also, each of your phone numbers are confined to a specific lane. Don’t you wanna make an outbound call and show the main number as the caller ID?

There is a better way and it is called a PRI.

What is an ISDN PRI?

An ISDN PRI or, PRI, is a digital dial tone service allowing up to 23 simultaneous calls using DID’s (direct inward dialing phone numbers) and here’s how it works.

Using the highway example from above and applying it to the way a PRI works gives you this:

  1. A dynamic amount of lanes on your highway. Meaning, like an accordion, they can expand and collapse depending on usage (automatically), thus saving tons of money right off the bat.
  2. Any car (phone number), at anytime, can travel across any lane it wants. You can even have the same exact car traveling in any number of lanes at the same time. So now you can afford to have A LOT of cars and I mean A LOT becuase they are cheap!

Why do you want A LOT of cars? Becuase cars are awesome! For example, we have hundreds of numbers (costing approximately $3.00/mo. for 20 different phone numbers.)

With numbers this inexpensive, we can now put a different telephone number on each and every advertisement as a way to easily track the success of the advertising we are doing and better decide where to concentrate our efforts. If a number isn’t being called, we can safely take down that advertisement and make the advertisement that is generating calls even bigger!

Every employee has a DID or, direct dial number, on our ISDN PRI. This means that if you were to call it, the number would ring the phone on my desk and not create additional load on the receptionist. I might give this number out to important clients, or friends or family. When I make a call, my phone can show either my DID’s number as the caller ID, or the main phone number of the company.

Every employee also has a personal fax number. No more sifting through the main fax machines many printouts and advertisements. You can either have a fax machine at your desk now and your own private number, or the faxes can go right into the inbox of your email and save a lot of paper. This makes faxing confidential documents completely secure. Can you now see the resources you will be saving?

What does an ISDN PRI phone system cost?

As you can see from the chart below, the numbers speak for themselves. No pun intended 🙂 DID’s are so inexpensive becuase they don’t need to come with a line or, lane, attached to them.

-line charges
-block of numbers (DIDs qty.20-24)
$380-600($19-$30/line)N/A $299-$450only $1.99
-Inter/Intrastate usage/minute
-10000 minute/month@average cost
$.050 -.085/min.
$345 (can be free with SIP)
$900 $1000
-recurring maintenance
-add a line or DID
$19-$30/line $2-$4/block of 20 DID’s (#s)

We all know that the one lane one car approach is ridiculous. There just isn’t enough real estate to go around for that economic model. Well, with business telephone line capacities that exceed the threshold I outlined above, a shared digital PRI or SIP circuit approach is the smart choice for many to make. By using this technology with your current, or brand new telephone system, you will positively affect your bottom line in a big way.

An ISDN PRI supports 23 channels, not numbers, for voice traffic via a T-1. If you need more than 23 channels then you can get 2 or more PRI’s. SIP offers over 30 channels. You can run 20-60 numbers over one PRI or SIP circuit simultaneously. However, there could be as many as 200 different ISDN telephone numbers that use those channels at any given time. This allows for better call center backup, overflow and alternate routing. Digital in nature, PRI’s and SIP trunks are equally good at handling voice or data. PRI and SIP circuits have become the chosen access method for business voice traffic.

Here’s what you get with ISDN services:

  • Elimination of pricey inbound/outbound voice lines
  • Virtual numbers will eliminate long distance charges
  • Routing of faxes more efficiently
  • Retaining and porting of existing numbers to your new PRI or SIP circuit
  • Consolidation of internet access on same “pipe”
  • Scale-up easily with minimum cost
  • Voice, data, video, and fax on PRI or SIP T1 communications circuit
  • Free enhanced features, i.e… Caller ID and DID’s (Anyone can have their own private phone #)

When ordering your ISDN PRI or SIP circuit, give us a call and we can help you decide what would be more efficient for your business. We offer PRI and SIP circuit solutions everywhere in the entire world at the best rates possible! Call us or click ‘Request a Quote’ at the top right of this page today!

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