This is a method of providing a phone service to people over the Internet. This type of service moves the traditional phone switch off site and allows more than one company to use a particular switch.
In order to make phone calls via the Internet one’s device has to be compatible with Softphone software. In example in order to call from a PDA using VoIP technology one has to install Softphone software, in order for it to work properly, PDA has to have Softphone compatibility.