On Wed, 2 Jan 2013, ned+ietf@xxxxxxxxxxxxxxxxx wrote: > At one point there was something that said one phone in each home had to be > directly wired without a plug. I don't know if this was a regulation, a phone > company rule, or just a suggestion, but it also fell by the wayside after > Carterphone. May have varied by baby bell, but in Michigan, you could have as many jacks as you wished, but you had to lease them all from the telco. There may have been a rule about having at least one hard wired phone, I don't recall. In those days, the telco owned and was responsible for all inside wiring. > I certainly saw acoustic coupled equipment in use long after Carterphone, but > in my experience it was because of general intertia/unwillingness to do the > necessary engineering, not because of the lack of connectors. Probably more to do with portability of accoustic couplers and the lack of provisioning in motels, etc. for jacks.