If a VOIP provider wants to avoid the label of telephony carrier, they should be strictly end-to-end service with no connection into the global
PSTN infrastructure. An example of this would be enterprise internal phone systems, designed to propagate calls within a single corporate entity.
Other examples are the INOC-DBA service which many NANOG members use http://www.pch.net/inoc-dba/ And both SIPPhone http://www.sipphone.com and Free World Dialup http://www.pulver.com/fwd/ have been operating in a similar way for a couple of years. These last two are now expanding by also offering PSTN connectivity, but they are rooted in a non-PSTN VoIP service. Many groups are setting up their own similar systems based on the ready availability of SIP compatible phones and PBX software like Asterisk http://www.asterisk.org. The Internet is fundamentally a network of IP routers. The PSTN is fundamentally a network of voice switches. A PBX is a small voice switch. Asterisk is software that provides PBX functionality on a UNIX PC therefore using Asterisk and the Internet, anyone can build their own network of voice switches for whatever purpose they want. I'm surprised there are not more smaller PC's offering this as some kind of an add-on service. Once you have a sizeable customer base using always-on broadband, why not help your customers set up always-on voice services. Of course in the absence of such support from ISPs, there is a vacuum which Skype is attempting to fill using non-standard software. --Michael Dillon