PRI Line is a type of Integrated Services Digital Network (ISDN) line that enables traditional phone systems to transmit voice, data, fax and video traffic simultaneously. It uses multiplexing/de-multiplexing techniques to carry 30 channels in a single circuit. Being an end-to-end digital line it gives better voice quality than analogue trunk lines and has a flexible billing system. With a fibre core ring, it also offers some redundancy and is not easy to tap into for snooping on conversations. Check our infographic to understand its working and the business situations for which it makes a good choice.