PSTN uses analog signal transmission over copper loops. Companies and individuals have used these landlines since the introduction of the public telephone system, and they remain mostly unchanged despite vast technological advances in communications technology.
Though PSTN is fairly reliable, it was created before cell phones and wireless internet usage became common for businesses and consumers. Compared with VoIP, landline phones are inefficient and not flexible enough for modern businesses. For example, PSTN uses copper wire, so when an individual makes a phone call, no one else can use that portion of the line. Call centers and companies that do most of their business over the phone must maintain many phone lines with PSTN — or they could purchase a single VoIP account. Learn More.