VoIP does require a service provider presence on the Internet in order to function. So the reliability of your service will depend on the ability of your service provider to maintain this presence. Most providers have considerable redundancy built into their servers and other hardware. This means that if they do experience a problem, you will likely never be aware of the fact. Their backup systems are designed to take over almost instantly in the event of a failure, so it is likely that the worst problem you would experience would be a slight interruption in service. This would be similar to a call “breaking up” or being “dropped” by a cell phone, but is not nearly as likely to happen with VoIP as it is with cell phone service.
