What is a PRI line?

A PRI line, or Primary Rate Interface line, is a telephone line that uses the PRI standard in telecommunications.
PRI is a standard that enables traditional phone lines to carry multiple lines of voice and data.
A PRI line provides a physical connection to the Public Switched Telephone Network and uses circuit switching to make voice connections.

The Primary Rate Interface telephone line, or PRI line, and has been the standard in telecommunications services for decades. But what is a PRI line exactly, and what advantages does it offer an enterprise over other telephony options? Here’s a brief introduction to “What is a PRI line?” that provides an overview.

A PRI line is a telephony technology to support voice communications. PRI is a standard interface of Integrated Services Digital Network (ISDN), a telecommunications standard that allows traditional phone lines to carry voice, data and video traffic. Using multiplexing and de-multiplexing technology, a PRI line can deliver multiple lines of voice and data as electrical signals over copper wire. Voice signals on a PRI line must be routed through a traditional telecommunications company. As a higher-capacity service carried on T1 or E1 trunk lines, a PRI line tends to be used by enterprises vs. private individuals.

What is a PRI line vs. SIP line?

A PRI line offers a physical connection to the Public Switched Telephone Network (PSTN), while a SIP line provides a virtual connection. A PRI line is a circuit-switched system, while a SIP line is a packet-switched connection.

What is a PRI line’s greatest benefit?

A PRI line tends to provide a higher Quality of Service (QoS) than analog or SIP lines. PRI circuits enjoy dedicated bandwidth that can’t be used for anything else, while SIP trunking may have to compete with other bandwidth demands.

What is a PRI line’s biggest limitation?

A single PRI line can only handle 23 simultaneous calls; enterprises requiring more calling capacity will need to purchase additional PRI lines.

What is a PRI line’s scalability?

Compared to the easy scalability of SIP trunking, scaling a PRI trunking is not as simple. Adding a PRI line to accommodate additional voice traffic requires modifications to infrastructure that may take weeks to complete.

What is a PRI line’s security rating?

A PRI line is more secure than an analog line, as it is much more difficult to tap into them to intercept conversations, and can be more secure than a SIP line, which may route traffic over the public Internet.

What is a PRI line with Spectrum Enterprise?

As a leading provider of fiber solutions for America’s enterprises, Spectrum Enterprise offers a highly reliable PRI voice trunk solution built on our extensive fiber network. A PRI line with Spectrum Enterprise offers unlimited local calling and scalable Minutes of Use packages as well as a suite of management, reporting and business-continuity features to keep employees connected and help maximize productivity.