I have tried Skype and Yahoo voice chat on a dialup and there is really a big difference on the delivery and connection. It's just that most softwares available now for communication purposes were built on the 128 kbps connection benchmark. And I heard soon that the broadcasting companies will be dealing with a big problem (theveniceproject) like what most telecommunication companies experienced with skype.

You can upgrade to either a faster connection as it's the only way to really feel the VIOP advantage.