Signs are pointing to business markets making the switch from legacy public switch telephone networks (PSTN) to IP phone services. The FCC recently reported that between 2008 and 2011, VoIP subscriptions increased at a compound annual growth rate of 19%, while switched acccess lines declined nearly 9% per year.

Enterprises everywhere are preparing to make the change. This all leads to the question, “Is the PSTN a thing of the pas?”

“The use of the POTS infrastructure [has] plummeted in the last decade… as [customers] switch to VoIP alternatives, wireless services and other forms of digital communications,” said Bob Quinn, AT&T's senior vice president for federal regulatory and chief privacy officer in a blog post. “We requested that the FCC oversee… this IP transition to capture and address the operational, technical and policy issues that necessarily will arise as we go through the process of retiring and transitioning away from TDM technology and services.”

The natural decommissioning of voice switching technology that has occurred over the past 10 years has led service providers to adopt VoIP technology for a fraction of the cost of maintaining their phone switches. As a result, many business customers are taking advantage of IP phone services without even realizing it.

If service providers are making the first move to kill the PSTN, enterprises will have very little to do to prepare. While hesitation around VoIP services has historically centered on voice quality and reliability questions, those concerns are going out the window as VoIP has matured. Businesses are realizing that VoIP is not a different technology, it's just the evolution of the telephone.