Contact a rep

Primary Rate Interface (PRI)


Get voice, data, and video with a direct digital connection to a Verizon central office.


Support sites with legacy ISDN PRI connectivity.

Many enterprises are migrating their voice services to VoIP technology while keeping a portion of their services connected with ISDN Primary Rate Interface (PRI) circuits. This could be for PBX compatibility or other reasons. 

With our wide-ranging networking solutions and decades of experience and thought leadership, we’re the right partner to help you put it to work for enterprises.

What is ISDN PRI?

An ISDN Primary Rate Interface (PRI) is a legacy technology circuit from a business site to connect directly to a Verizon voice switch providing voice, data and video services in increments of 1.54 Mbps.

How does ISDN PRI work?

An ISDN PRI circuit connects a business site directly to a Verizon Central Office switch and splits a 1.544 Mbps circuit into 23 voice/data channels and 1 signaling channel. These channels can be used individually or combined to provide voice, data or video services. This service is being replaced by IP based technology and services and is used primarily by businesses today to connect legacy PBX systems that are not yet IP enabled.

Features & benefits

ISDN PRI gives you a clear digital connection for high-bandwidth applications, with fast call set-up.

  • Simplify. Handle local, long distance, voice and digital data calls over the same PRI connection
  • Elastic. Provision bandwidth as you need it, and allocate capacity for inbound and outbound calls.
  • Reliability. With ISDN PRI, you experience the speed and reliability of Verizon.



years of experience managing networks


countries where we manage networks


experts to support your needs

Services and/or features are not available in all countries/locations, and may be procured from in-country providers in select countries. We continue to expand our service availability around the world. Please consult your Verizon representative for service availability. For further details please contact us.