How is the VoIP offered from the local cable company any different than Vonage? It's not. They both use the same protocol (VoIP: Voice over Internet Protocol), they are both used through the cable lines. The cable company started offering it to compete with Vonage, make more money. It does not differ, Vonage does not use more bandwidth than the one the cable company gives you. If the power goes out, the one from the cable company wont work either. How are you going to power the box that you plug the phones into? Both the phones from the cable company and from Vonage need those boxes to function, and without power, they canot function.
There are several different codecs that Vonage and the like use. They are 30kbps, 60kbps, and 90kbps. Most people use the 30 one, so lets use that as an example. Remember that there are 8 bits in a byte. Most calls over VoIP send packets at about 78bytes and the standard call will send about 50 bytes per second, so that comes out to some 3900bytes per second, and 234 kilobytes per minute. 1,024kb in 1MB, 1024/234=4.376MB per minute. If you have standard Comcast or other cable, you are getting at least 3Megabytes per second. This isnt very much bandwidth to be concerned with. My office uses VoIP which works the same as Vonage and the rest, and this is not a cause for concern on the bandwidth.
They ALL do this, not JUST Vonage. Vonage was just the first company to do this, so people are hatin on them. You can also keep your current landline number with Vonage, as with everyone else.
EDIT; Vonage for small business, where you can call outside of the US (to Puerto Rico and other places) it is $39.95. For unlimited home calling within the US, it's $24.95. If Shaw is $45.99, I dont think the $20 a month is worth it. And what does Shaw have over Vonage? Not much, except that it's more expensive. And if something goes wrong, it's not Vonages fault, they just send you the box to plug in, it's the cable companys fault, because it's their internet line. They send out service calls with their phone service, because the men they send out to fix it are just cable repair men. You should all do some more reading on Vonage and VoIP and anything else before you start making gross assumptions.