On Jan 2, 2013, at 5:07 PM, Dave Crocker <dhc@xxxxxxxxxxxx> wrote: > > On 1/2/2013 1:34 PM, ned+ietf@xxxxxxxxxxxxxxxxx wrote: >>> Now, your point about rewiring the jack may in fact be the reason for >>> _post-Carterphone_ acoustic couplers, but it was indeed at one time illegal >>> to connect directly (other than AT+T/WE supplied equipment). >> >> I'm skeptical about this last part. Prior to the advent of RJ-11 Bell System >> line cords used a large polarized four pin jack. After Carterphone all sorts of >> stuff started to appear to accomodate these, including extension cords, >> plug-jack passthroughs, and even "cube taps". > > Acoustic couplers date back farther than the 4-pin plugs. > > As I understood the AT&T claim, they asserted a need to protect their network from misbehaving electronics and so required all interfacing to be through the handset that they provided. > > Hence the overlay hack of an acoustic coupler. Not unlike MIME... > > >> 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. > > It was usually enforced rigorously. A given field tech might choose to overlook a local mod, but they were authorized to remove such things. > > So in my apartment, I installed a shutoff switch to the line, to be able to sleep through attempts by my boss to call me in to work an additional shift as a computer operator, at UCLA, around 1970 -- if I answered, I was required to come in. Remember there was no caller ID in those days. > > The tech who needed to work on my phone service was very clear that he was supposed to remove it. After checking that I had handled the wiring acceptably, he looked at me and said "so if I remove this, you'll probably just reinstall it, right?" He then left it in place. I grew up in South Africa, with Telkom, the state run monopoly. Connecting anything other than a telephone was illegal, with (IIRC) the possibility of jail time. You would have to rent the phone unit itself from Telkom by going to the post-office and filling in a form, then waiting few a few weeks to months. If yo unmoved you had to return the unit and rent a new one… South Africa used weird jacks, shared with Benin, Burundi, Cameroon, Central African Republic, Cook Islands, Liberia, Namibia and Serbia. (some pictures here: http://www.networkmuseum.net/2011/06/phone-plugs.html). The pins were made of some very soft metal (possibly high in lead, based upon the speed at with they would tarnish and appearance of the oxidation) and the wipers in the socket from a dissimilar metal. This would result in very poor / flaky connections, and kicking the jack to wiggle / reseat it was a common practice. Fun times... W > > d/ > > -- > Dave Crocker > Brandenburg InternetWorking > bbiw.net > -- Eagles soar but a weasel will never get sucked into a jet engine