On Wed, Jun 5, 2019 at 11:38 AM Fred Cisin via cctalk <cctalk@classiccmp.org> wrote:
> Prior to Carterfone V Western Electric, (1968) . . . > There were DAAs RENTED by TPC ("The Phone Company" (cf, "The President's > Analyst")), dialers RENTED by TPC, and acoustic couplers in the > after-market. [...] > Prior to Carterfone, you had acoustic couplers, switch-hook solenoids, > DAAs RENTED by TPC, and only TPC dialers. Once direct connection was > available, you got things like the PhoneMate dialer, and moving piece of > mylar with marks and photocells. > The 1968 Carterfone decision did eventually result in customers being allowed to hook their own devices up directly to the phone line, but contrary to what a lot of online sources including Wikipedia claim, that didn't really happen until the FCC promulgated the Part 68 regulations in 1975. The immediate reaction to Carterfone was that in 1968 Bell created a "foreign attachment" tariff, which allowed customers to lease the type CBS or CBT Data Access Arrangements (DAA), which included protective coupling circuitry, and connect their own devices to the network only indirectly through the DAA. Starting in 1975, equipment could be sold for direct attachment if it met the Part 68 requirements and was registered with the FCC. The equipment had to bear a label with the Ringer Equivalency Number (REN), and the subscriber was supposed to notify the phone company of the RENs of the devices they were using. I don't know anyone who actually did so. There is very little detail on this available online, but I found that Google Books can show relevant excerpts from _Communciations Law and Practice_ by Stuart N. Brotman, 2006 printing (originally published 1995). See pages 5-19 and 5-20.