Why Is It Called VoIP?
As the full name - Voice over Internet Protocol - suggests, the technology is simply called VoIP because it takes voice services away from their own dedicated hardware. It used to be the case that every voice called was serviced over the public switched telephone network. There are a few downfalls to this sort of dependence on one system. First, while it initially had a much broader reach, the PSTN no longer has an advantage in terms of customers reached than VoIP services can deliver. Second, the PSTN is subject to different regulatory policies and is far less flexible.
VoIP Isn't Limited To Internet Users
One of the early disadvantages of using a VoIP service was that it was only available as an Internet-to-Internet connection. This slowed the adoption of VoIP as a true alternative to traditional PSTN services. Of course, just judging by the widespread adoption of VoIP by businesses and consumers alike, it's clear that this is no longer an issue.
The reason for this is IP backhaul. To put it simply, calls that originate using VoIP aren't stuck on the networks that make up the Internet. They're now able to connect to the switching centers that are at the backbone of the PSTN. At this point, calls are relayed from the Internet to traditional telephone networks, meaning that a call can be place or received over VoIP at one end and still have a traditional telephone user on the other end.
This has spurred adoption of VoIP in a few areas, such as:
Business telephone systems
All of these customers and more are now turning to VoIP at an increasing rate. Without the barriers to entry that used to exist, they see the value in VoIP.
Why Use VoIP?
That brings us to our last point - that VoIP is simply more valuable than traditional calling services. The reason is, of course, cost. VoIP offers more flexibility and better service without having the same costs of PSTN-based services. If you have Internet access, then you have access to install a VoIP system. These systems are also typically easier to maintain, since they run off of the Internet service you already have set up rather than needing their own network. This reduces support costs and leads to less downtime, resulting in increased user satisfaction.
Overall, anyone in need of a phone service should consider VoIP options. Whether it's for a small business of 15 employees or a sprawling call center with thousands of calls per day, chances are that VoIP is the more effective route.