PRI is a type of digital telecommunications service used for connecting a customer’s premises to the telephone company’s central office. It’s used to connect to broadband backbones that link local and central exchanges or network switches. PRI provides 23 voice channels and one signaling channel over a single physical circuit, allowing for the simultaneous transmission of multiple phone calls and signaling information. It is typically used by medium to large-sized businesses that have a high volume of incoming and outgoing calls. PRI is especially useful for businesses and organizations that require a large number of phone lines, such as call centers or offices with many employees.