The PSTN line has been around for more than 100 years and is still a critical part of communications infrastructure. It is a simple two wire copper cable that carries the voice service and, more often than not, an ADSL broadband or FTTC service. It is reliable, doesn’t require any power, can run over large distances and is simple to connect. With such a huge existing country-wide infrastructure lines can often be installed very quickly.
Installation and monthly costs have been rising though meaning that for multiple lines, other than essential emergency ones, VoIP (Voice over IP) is a much more cost effective solution because it uses the digital network that nearly all event sites now have.