Telephone System Integration - VOIP
Voice Over IP
Voice Over IP communication was popularized by individuals who communicated over the internet using specialized software on their PCs. Even though call quality was moderate, it let them avoid the high phone carrier tariff costs in calling from country to country. As technology improved so did call quality. A free program, Skype, became a standard for PC to PC communication.
New phone systems were developed to use internet cabling from phones to their central phone systems. The technology allowed organizations to connect remote offices to the central phone system using the internet and avoid high phone costs. Just by dialing an extension you can reach across offices around the world.
There are also many companies (like Vonage) that offer VOIP solutions for consumers and small businesses. A normal phone can be connected to your internet network and make local and long distance calls for a monthly fee.
Connecting to outside phone lines
Every VOIP phone system or network must connect to the local phone provider to make calls outside the phone system. For example, I can call another extension in the company using VOIP, but when I dial a 9 to get an outside line, there is a gateway connector to our phone system that interfaces to normal phone lines.