SIP Trunking Vs PRI

Thanks to new developments in communications technology, today’s market offers companies like yours two types of phone systems that connect your business to the world. However, the two are not the same when it comes to time, money, versatility, and equipment. That’s why it is important to understand how each system operates and which one is the best choice for your business.

What is PRI?
PRI is considered the traditional method of handling your office phone communications as it has long been the standard for providing telecommunications services to offices. It relies on the Public Switched Telephone Network – requiring a circuit switch to allow a call to connect to your office – and uses a physical phone line to work. Each line has a total of 23 voice channels that can be used to handle simultaneous calls. However, connections are purchased per circuit of 23 channels, and this requires the additional cost of new hardware in order to connect to your existing phone system. Thus, your business must install multiple lines in order to increase your call capacity.

What is  SIP Trunking?
SIP trunking allows your business to virtually connect to the Public Switched Telephone Network and routes all VOIP calls and unified voice data over your internet. One of the most significant advantages of SIP Trunking is its ability to combine data, voice, and video in a single line. Therefore, eliminating the need for separate physical media for each mode.

Unlike PRI, SIP Trunking does not limit the number of voice channels you can use, and you are not required to purchase additional hardware in order to increase your call capacity.

Instead, the amount of calls you can send and receive simultaneously is only limited by the amount of BANDWIDTH your company has purchased through your internet service provider. Additionally, only one sip trunk is able to route all simultaneous calls a user needs to make. If you need to increase your call capacity, you only need to purchase more BANDWIDTH and you are all set!

The SIP connections are sold as per call path. Buy more SIP Trunks to meet the increasing demand of your company to add more users (1 SIP trunk per 2-3 users) – making SIP Trunking a much more cost-effective operating system for your telecommunications.

5 Major Differences Between PRI and SIP Trunking



  • With PRI, you are required to pay additional per-minute fees in order to make any long distance phone calls.
  • SIP Trunking, however, allows you to make unlimited local and long distance calls as part of the plan you purchase using the DID’s.



  • PRI is a physical phone line with a limitation of 23 voice channels for use and it requires local termination. New and costly PRI-circuit is required for multi-site offices. Installation of multiple phone lines is required to increase the capacity of the existing telephone system.
  • With SIP Trunking, there is no new hardware to install as you expand your business. All you need is an internet connection and a phone.


  • If a PRI fails, you potentially not only lose the hardware but all the important data too– leading to a costly repair.
  • With SIP Trunking, your information is secured in the data center with a fail-proof rate of 99.99999%.


  • PRI systems often require that you pay for additional features and services.
  • SIP Trunking allows you to use and customize features supported by your PBX at no additional cost, saving you even more money.

Disaster Recovery

  • PRI requires you to re-route your calls to a pre-determined alternate location, which can lead to additional service charges.
  • With SIP Trunking, you decide which phone numbers to send calls to in the event of an emergency. Route calls to any numbers at no additional cost.

Our Answer

So what’s the difference between pri and sip Trunking? When it comes to your company’s telecommunications, sip Trunking is the smart choice.