Back when I was working with such things, well over 25 years ago, we had two types of networks we discussed. We talked about PSTN and CSTN. The latter was Circuit-Switched Telephone Network while the latter was, in fact, Packet-Switched Telecommunication Network. The latter had evolved from telephone to telecommunication as a consequence of the increasing use of DS0 and DS3 networks among businesses.

It's worth keeping in mind that, back then, the telephone network to which we were accustomed was, in fact, primarily a voice-comm's network, and that IP had been a construct allowing data networking on the voice network. The term "circuit-switched" dated from the days when, in fact, there was a physical circuit connection between the instruments at both ends, which had, in fact, been eliminated through the use of TDM decades before IP became a viable concept. At that time, the pulses that the instrument generated by dialing a number actually caused a stepping relay to increment its position to one of ten steps, and, incrementally, progressed to a point at which there was a physical circuit connected between those instruments once both were "off-hook."

I guess nomenclature evolves right along with industry culture.

RE