Many people call bandwidth "SPEED". They are two totally different things. It's just that if you have more bandwidth, you can send more packets at a time, and therefor it can download/upload "FASTER". But voice (Phone) is in real time. If it takes you 4 seconds to say a sentence, 3mb dsl isn't going to get it there any FASTER than 1mb dsl. Bandwidth is not SPEED. For what it's worth, Voip using the g.711 codec, uses just less than 100kb of BANDWIDTH. Yes, that's KILO. Believe it or not, using the g.729 codec, you can run Voip over a DIAL-UP Internet Connection. I've done it. It works.

But speed is indeed an issue. Not bandwidth. Speed is also referred to as "LATENCY". When voip reaches past the 150-200ms latency range, you get problems. Remember; voice is real time. You can't RESEND a voice packet like you can a missed packet in a file you're downloading. Now; for what it's worth, a really good 3g cellular internet connection is pushing that 150ms latency time. So; if you have that 100-150ms (Possibly more on a bad day) to deal with...... Then, you throw in the additional latency of using your home WIFI........ You're asking for trouble. Will 4g be better? Yes. But you have to realize something VERY IMPORTANT....... Cellular was not designed with internet voice packets in mind. Why should it? It's a cellular phone. It's already taking care of your voice calls. Now; FWIW; the newer 4g is being developed to make all your voice calls truly voip. But just like I've said about ma'bell and similar; they have their own dedicated network. When you have a dedicated network, you can accomplish a lot. Traditional VOIP, like VoipO is not on a dedicated network. It's on the INTERNET. And your voice packets have to compete with the emailers, gamers, netflix downloaders, etc.... But again; SPEED and BANDWIDTH are not the same thing. Your 1mb dsl is more than enough for Voip. Unless the latency (Speed) is too slow. Or; you're talking to grandmom while downloading a big torrent file. But most people who get into these conditions know how to use QOS to help a little.