Businesses might be stuck using their current legacy phone systems that rely on older equipment. They may not be sure how to upgrade or transition without spending a lot of time and money on implementing new ones.

A SIP (session initiation protocol) trunk to PRI (primary rate interface) gateway, also known as a SIP trunk to PRI converter, connects today's SIP trunking phone services to legacy PRI phone systems. This is essential for businesses to keep older equipment that is still functional. It also helps businesses sign up for a new phone service while being able to use their old phones.

Many organizations still have these older phone systems. But they want to begin using VoIP (voice over internet protocol) service through SIP trunking. Thanks to SIP trunk to PRI gateways, this is possible.

This process can be a money-saving solution for businesses that have a lot of equipment to update. It's also a solution for businesses that may need to wait a while before investing in major equipment upgrades.

Read on to learn more about why your business needs a SIP trunk to PRI gateway.

What Is a VoIP Gateway / SIP to PRI Gateway?

A VoIP gateway allows you to convert between a traditional telephone connection and a modern VoIP connection using SIP. A PRI gateway translates SIP to something old technology can understand and use.

PRI systems rely on T1 lines to deliver voice and data and have been available since the 1980s. These systems use old hardware designs that were widely used in a variety of industries until SIP and other new systems became more common. In order to use PRI systems, you needed service delivered via these T1 lines to your office from a local telecom company.

T1 lines have a higher data capacity than the landline wiring commonly installed in homes, so they were very popular with businesses who often dealt with high call volumes.

SIP is a type of networking language. PRI gateways work by feeding the equipment information in the right format, so the data looks like it would be arriving over an ISDN (integrated services digital network).

While a SIP trunk is entirely virtual, PRI connections are actual hardware. They required a specially installed line placed in office buildings to carry the additional data required for a call center to operate. As such, this was typically a service only larger businesses with high call volumes would be interested in using, such as telemarketing companies or the customer service departments of large enterprises.

SIP trunks, in contrast, use networking technologies that exist on the internet. They don't require a separate physical line. Instead, they can "live" on currently available infrastructure in place to deliver internet service. It's easy to switch vendors because there's no dedicated physical line linked to the phone company that needs to be disconnected, and there's usually no need to install special wiring to add SIP trunks.

There are two types of gateways:

Analog: Analog units allow you to use regular landlines with a VoIP gateway. This is helpful for businesses with existing landline phones that want to upgrade their network

Digital: Digital units, on the other hand, allow you to connect one or more digital lines to one another. These are normally used by large companies to accommodate a large number of phones

While this process usually means a lot of extra equipment, it is the only way to leverage VoIP features like free long-distance calling, visual voicemail and other features without having to give up your landline. Alternatively, you can abandon your landline and start fresh with a business phone system.

Here are some other names for a VoIP gateway:

● PRI gateway

● IP media gateway

● SIP gateway

● Voice gateway

● TDM (time-division multiplexing) gateway

● PSTN (public switched telephone network) gateway

● ISDN gateway

● Digital telephony gateway

● Analog gateway

Features of a VoIP Gateway

VoIP gateways are simple. They connect traditional landline PSTN audio into data and effectively connect a traditional phone system to an IP network. This makes them an essential part of any modern business phone network that still relies on traditional phone infrastructure or equipment.

VoIP gateways offer several features:

Unlimited Long-Distance Domestic Calling

If you make a call to another state with your landline phone, your service provider will charge you a per-minute rate for the call because you are taxing their copper-based network. When calls are made over VoIP, that problem does not exist because data can travel any distance easily.

If you or your employees make a lot of long-distance calls, then a VoIP gateway can help reduce long-distance calling charges.

International Calling

Many VoIP services charge a lower per-minute rate for international calls than their landline counterparts. However, 8x8 offers plans that let you make unlimited international calls to over 40 countries. This is especially useful for companies with employees, contractors and customers located overseas.


Many traditional landlines allow you to make three-way calls. Once connected to a VoIP system, that limit goes up substantially. If your phones are connected to the internet via a VoIP gateway, you can hold conference calls using 8x8 Virtual Office with 15 participants at once.

Being able to connect a large group of people over the phone for a large meeting can increase your team’s productivity.

Mobile App

With an all-landline setup, you can only use your landline number if you are physically in your office. However, VoIP systems offer a mobile app that lets you make and receive calls from your landline number no matter where you are located. All you need is a smartphone or tablet, with either iOS or Android, and you effectively have your old landline number available for use on your personal mobile phone.

8x8 also offers Softphone, which transforms your desktop or laptop computer into a feature-rich, web-based phone.

Why Businesses Require a VoIP Gateway

A VoIP gateway provides various benefits for businesses of all sizes:

Versatility: VoIP gateways include the proven reliability and call quality of a landline, but they also let you connect those lines to the internet and enjoy all the features of VoIP

Cost savings on calls: When your landline is connected to the internet, you can enjoy features like unlimited long-distance calling both domestically and internationally. If you make and receive calls from all over the country and across the world, then you will definitely see huge cost savings compared to simply using your office landline on its own

Mobility: Because VoIP services offer mobile apps for making and receiving calls, you can take your business phone number with you wherever you go on your Android and iOS device

Benefits of a VoIP Gateway for Businesses

If you have older hardware that relies on PRI standards, a SIP trunk to PRI gateway could buy you some additional time to use your older hardware. Without a PRI to SIP gateway, you'd have to purchase new equipment, which could be a major investment for organizations with a lot of phone infrastructure and equipment around.

This way, you can use a PRI to SIP gateway to help with gradually phasing in newer phone equipment that uses SIP or you could wait to invest in new technology later when funds permit.

Using a PRI to SIP gateway might also be a helpful strategy for companies that are skeptical of SIP and want to make sure the service is right for their business before making the leap and purchasing a new phone system. Or businesses that aren't sure what phone technology is the best fit and want to take the time to try different types of phones on a smaller scale while using older equipment for most departments' telecommunications needs.

What Makes 8x8 VoIP Gateways So Reliable

VoIP and PSTN gateways work by serving as an interface between networks. They help translate data and information from one source into a form the other network can understand. Then the gateways send the data along to the right recipient.

Networks cannot go down, and communications must be instant. 8x8 understands today's data and communications demands and provides a robust, reliable cloud solution in the market.

Take the Next Steps

A VoIP gateway is a useful device for business owners who don’t want to do away with their landline setup but want to enjoy the benefits of everything VoIP technology has to offer. While new businesses might want to consider an entirely VoIP network—in many instances, it's their only choice—a VoIP gateway is a huge benefit to companies straddling the line between the traditional and the modern.

Choosing the right technology is crucial to a growing business. Take the uncertainty out of the equation by choosing a SIP technology provider that can scale to meet your business' needs, whatever they may be at any given time. Call 1-866-879-8647 or fill out the form below to request a no-obligation quote from an 8x8 product specialist.

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