SIP Trunks Replace Traditional Telecom PRI

Carolina Digital PhoneWhat’s overly expensive, set in its ways and headed down the road to obsolescence? It’s telecommunications via Primary Rate Interface, and if your business still uses this old-time voice delivery method, you might want to ask yourself why.

What PRI Is and Is Not:  PRI is nothing more than a form of digital circuitry that offers its users 23 channels or voice paths over a single signaling circuit. Because PRI connects directly to the , the call quality is good. Unfortunately, the entire PRI system calls for a substantial investment in cables and hardware. This makes it less than ideal for use in the modern business office.

Session Initiated Protocol Trunking: With SIP trunking, all calls route through the Internet, requiring no external hardware or circuitry. Instead of interfacing with the telephone company, the SIP trunk connects your organization directly to an Internet telephony service provider. This use of Voice over Internet Protocol, or VoIP, makes it vastly less expensive to operate while providing a flexibility that positions it well for modern business use.

Benefits of SIPWhen calculating the ways in which SIP outstrips PRI, several features come to mind. Chiefly, an SIP trunk provides:

A virtual connection. Unlike PRI, SIP trunking has no need for cables and termination hardware to connect each individual circuit.

  • Scalability. Perhaps the biggest selling point of any VoIP system is its ability to add capacity through nothing more involved than a simple software reconfiguration. With SIP, you’re dealing with only one network and one set of cables. With PRI, on the other hand, scaling up requires the installation of new circuits and hardware. This can take weeks to accomplish.
  • Savings. The already high cost of running on PRI will rise in line with the number of voice channels a company uses. An SIP trunking system, on the other hand, bases its pricing on actual usage, saving its users hundreds of dollars each month.
  • Reliable disaster recovery. The simplified setup of SIP eliminates the headache of recovering from telecommunication loss due to accident or natural disaster. Whereas the diversion of PRI calls to alternative locations can be costly and involved, the business that runs with an SIP-based telephony system can trust that its calls will automatically reroute to one or more functioning localities.Without question, the capability and cost-effective nature of SIP trunking have already far outstripped any benefits of the older technology. While VoIP rules the day, the death knell for PRI has already begun to ring.

When considering SIP Services for your telephone system call the experts at Carolina Digital Phone at (336) 691-2000.


For the past 35+ years, computers, advanced technology and solving problems with this new technology have been his business. In 1978, he graduated from Appalachian State University in Boone, NC with the first graduating class in the 16 North Carolina Universities with an Information Systems degree from the College of Business. For the last 14 years Nicky has served as the visionary leader and CEO of CAROLINANET.COM, a web hosting and server colocation data center and since 2004 the CEO of Carolina Digital Phone offering hosted telephone services and SIP Trunking. Read more at his LinkedIN page