Other than that, comparing TDM with VOIP is still incorrect, since they refer to different things.
Actually, comparing VOIP to TDM is spot on, and is the very core of this debate. When we talk about TDM we are talking about a real-time digital stream, the tried and true method of digital transport for voice for over forty years now. VOIP is a completely different paradigm (yeah, I hate that word too, but it fits) in that it uses a packet based (not real-time) protocol to carry voice. This was first concieved of decades ago, but it was never viable in the past because we didn't have fast packet based networks with low enough latency to be usable. Now we sort of do...
Getting people to understand real-time vs. packet based can be a challenge. Try explaining to a CG netwoking type that a true T1/DS1 carrying voice channels has no error correction, forward or back. They think only in terms of packets, so the idea of an eight (or seven, back in the day) bit sample with a usable life span of 125 microseconds (1/8000 of a second, otherwise known as "right now") is something they can't wrap their heads around. They insist the idea is crazy, and not a good way to do it. I guess all those crystal-clear long distance calls we enjoyed for so long weren't as good as I thought they were. Sigh.
I think I just saw the horse move.
