CSDS - ISDN Primary Rate Interface (PRI)


Circuit Switched Data Services (CSDS) ISDN (Integrated Services Digital Network) PRI is a local exchange access service that creates a direct digital connection to a Verizon central office to provide voice, data, image, and video services on a single circuit or line. Customers avoid the need for individual dedicated circuits for different applications.


  • Control Costs. If a dedicated T1 is being underutilized, it may be cost effective to replace it with a PRI and route calls over the network rather than pay the entire cost of the T1.
  • Disaster Recovery. Circuit switched capability can provide alternate paths in the event of an emergency. Protect the reliability of your communications with options for backup configuration.
  • Host Computer Access. To access host computers, customers can use variable, large bandwidth for high speed data communications.
  • LAN-to-LAN connection. Large bandwidth is essential for heavy graphics and data intensive applications (i.e., Computer-Aided Design (CAD)/Computer-Aided Manufacturing (CAM)).
  • PBX Trunking Efficiency. Call-by-call service selection can reduce trunking requirements and allow customized time-of-day selection of service.


  • Flexibility. ISDN PRI gives you fast, flexible access to services such as direct inward and outward dialing, WATS, toll-free , and circuit switched data, providing clear, digital transmission for voice and data communications. Gain the flexibility of call-by-call service selection that increases trunking efficiency.
  • Feature Rich. The call-by-call service selection and individual calling line identification capabilities offer a cost-effective, feature-rich method of local access for applications such as PBX trunking, host computer access, LAN-to-LAN connections, and videoconferencing. Increase call handling efficiency with calling line identification—a feature available even to PBX users. Benefit from planned enhancements like additional telephone number capability.
  • High Speed. ISDN PRI transmits large volumes of data, video and enhanced voice communications requiring higher transmission capabilities such as videoconferencing.
  • Video Conferencing. Large bandwidth enables quality video resolution and allows for faster screen refresh. Save on travel expense by using videoconferencing with full motion virtual meetings.

Services are not available in all areas. Please consult your Verizon Business representative for service availability and complete details.