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PRI vs. SIP trunking: What’s the Difference?

Last updated: 12 Apr 2023
PRI vs SIP Trunking

Let’s face it. Your company needs a robust communications system to operate. Most businesses still rely on a customer being able to pick up the phone and talk to someone live. The choices you make about your telephony systems can have a meaningful impact on your revenue, employee productivity, and future growth. So what are the options?

On the one hand, you have Primary Rate Interface (PRI) trunking. On the other hand, there’s Session Initiation Protocol (SIP) trunking. Both methods use a PBX setup to keep your business connected with customers. So what makes them different? In this article, we’ll cover the basics of PRI and SIP trunking and learn what the differences are between them.

What is PRI trunking?

Primary Rate Interface (PRI) trunking is a traditional business phone system that’s been around since the 80s and still works well for many companies. PRI uses copper wires to send analog signals to phones throughout your building. It doesn’t rely on data bandwidth to host calls, which is why it was historically touted as providing a higher quality of service.

Each PRI line can simultaneously support 23 separate communications (voice, data, or video) at the same time. It’s unlikely that all 23 lines will be active at once. With that in mind, businesses usually need to keep a set ratio of users to PRI lines. This will prevent issues from having too many users at once.

When an organization adds new users, they have to be mindful of their PRI limits. Adding a new PRI trunk can be expensive and cumbersome, with a company waiting weeks to add another communications line.

PRI trunking is a good option for companies that don’t have access to fiber-optic internet. It’s also great for those who don’t have enough bandwidth to support IP-hosted phones.

What is SIP trunking?

SIP trunking is a VoIP technology based on Session Initiation Protocol (SIP). SIP trunking is a hosted cloud service that allows users to communicate via voice, video, chat, or other methods over the internet. In this model, the business buys raw connectivity. The SIP trunk would likely connect into an onsite IP PBX to deliver advanced voice services.

There are a few reasons why you may want to choose SIP trunking for your company:

  • SIP trunking uses a VoIP line to initiate and end calls, but it also supports a variety of other transmissions, including SMS messages, video conferencing, and data transmissions. For companies prioritizing unified communications, SIP trunking provides the right technology.
  • You only pay for the number of SIP trunking channels you need, when you need them. If you need 23 channels, you pay for 23 channels. If you need 28, then you pay for 28. This flexibility could lower costs by up to 30 – 40 percent when compared with PRI trunking and integration with other communications tools.

Organizations that choose SIP trunking vs. a PRI need to be sure they have the necessary bandwidth, as well as sufficient network security. The quality of your communications matter, so choosing a vendor to help with SIP trunking should include considerations for these factors.

But there are great benefits to choosing SIP trunking. For one, it reduces maintenance requirements for your IT staff. It can also significantly reduce the cost of your telephone service. When used in a unified communications strategy, SIP trunking supports mobile and remote employees while driving increases in revenue.

The difference between SIP trunking and PRI

Choosing a communications service often comes down to the availability of onsite resources. Many businesses already have the infrastructure in place for a PRI, making it easy to install or upgrade their current phone system. On the other hand, a VoIP service like SIP trunking can simplify your communications system and bring it into the digital age.

To help choose between PRI and SIP trunking, here are a few things to consider.

PRI trunking

Since PRI trunking transmits analog signals through a physical connection, it doesn’t require any data or bandwidth to use. In other words, it’s a traditional on-site PBX phone solution. Despite being an older technology, PRI trunks are still common in businesses throughout the world.

Here are a few benefits to using a PRI trunking system:

  • Many businesses already have the infrastructure in place for PRI.
  • PRI trunking does not require a strong internet connection or high bandwidth.
  • Communication quality is consistent and reliable.
  • Calls aren’t susceptible to cyberattacks and other internet-related risks.

There are some drawbacks to PRI:

Requires dedicated lines and physical infrastructure to operate
Can be more costly than digital or cloud-based solutions
PRI can be subject to security risks like call interception and interference

While there are many providers who still offer PRI solutions, they’re becoming increasingly rare as more companies adopt digital solutions like VoIP or SIP.

SIP trunking

SIP trunking is a standard approach for handling the transmission of multimedia communications. As an alternative to PBX phone systems, SIP trunking is a way to support VoIP telephony with services hosted either on-site and managed by the IT team, or in a cloud server with a monthly subscription.

The benefits of including SIP trunking in a communications service subscription include:

  • Supports a wide variety of media types
  • Integrates with other platforms easily as an open standard
  • Supports multimedia data transmission, with multiple transmissions occurring simultaneously
  • Offers easy scalability and mobility
  • Includes measurable cost savings

While more businesses are adopting SIP trunking, there are still some disadvantages:

  • It requires a strong bandwidth connection; not ideal for businesses with weak internet.
  • If the internet goes out, your communications go with it.
  • SIP trunking can be susceptible to cyberthreats.

Despite these disadvantages, businesses have a lot to gain from making the switch to a VoIP system with SIP trunking. If cybersecurity is still a concern, here are some tips on securing your VoIP system.

Choose the service that’s right for you

There’s no one-size-fits-all solution for every business. PRI vs. SIP is ultimately going to come down to what works best for your company. Organizations that want to save money, improve productivity, and add on mobile connectivity should weigh out their options.

BlackPoint IT Services is one of the few technology service providers to offer a full suite of solutions. Your phone system should provide seamless connectivity no matter how many devices you have or how far away they are from each other. Still not sure what communication service makes sense for you? We can help. Contact us and schedule a free assessment for your phone system.