Most of the numbers touted by large analyst shops show how VoIP has gained wide scale entry into mainstream network applications. Enterprises have begun to trust vendor claims that VoIP offers advanced voice and data convergence features, in addition to dirt-cheap calling rates. According to Distributed Networking Associates, for example, this year marks the point at which more enterprises in the U.S. will use VoIP versus traditional telephony. Over 85% of enterprises either already have IP telephony or plan to install a VoIP system, Distributed Network says. By 2007, about 19% of all business calls will be made through a VoIP network, according to In-Stat/MDR.

For cable operators, the VoIP sector will account for 4.2 million new subscribers per year, which will generate $5.4 billion in sales for cable system operators by the end of 2008, according to analyst firm Kagan World Media. Traditional telephony providers and even DSL service providers are also looking at more than 50% VoIP growth rates per year, several analyst firms have reported.