All the home security systems that I am aware of require the use of a telephone to work. I suppose it *might* work under that broadband telephone service like Vonage, but you would probably have to ask to be sure, since the home security system siezes control of the phone line when you activate it.
To really be honest with you, it takes the police at least 45 min on average to respond to a home silent alarm, so a person who knows what he's doing can steal you blind in that time peroid.
I suggest you also have a audible alarm added to the system. In the very least, thiefs don't like going through your home when there is a 50db alarm blaring.