"What everyone is actually *selling* commercially, except for cable providers, is *not* VoIP; it's a subset of that: VoN; Voice Over Internet; where the IP transport *goes over the public internet*, and through whatever exchange points may be necessary to get from you to the provider.
This is utterly irrelevant to the topic at hand (What vexes VoIP users/providers). Further, it's ridiculous to say that something is a subset of something else, and yet not that something else. A1 cannot be a subtype of A without being A. A1 cannot be a subset of steak sauce without being steak sauce. Yes, it's a specific type of steak sauce, and is basically made of corn sugar, which may negate some of the issues with tomato-paste based steak sauces, but it is STILL a steak sauce, and is still relevant when talking about how many people put sauce on their steak as opposed to utilizing old fashioned steak rub.
Cable companies are selling you *one hop* (maybe 2 or 3; certainly not 12-18), over a link with bandwidth protected from whatever may be going on on the Internet IP link they're also selling you; and which is therefore guaranteed to have better quality than whatever "VoIP" service it might be competing with."
Better?
Not really, because you're still arguing a point that doesn't matter. Is it Voice? Is it IP? Then it's VoIP. A lot of the issues are still relevant, and certainly the number of users can be said to count. The number of hops doesn't matter one iota. Is it not email if you're only 1 hop away from your SMTP server? Nathan