On Wed, Dec 30, 2015 at 12:30 AM, Christian Gauger-Cosgrove < captainkirk...@gmail.com> wrote:
> > On a Number 5 Crossbar, your DTMF was never converted to dial pulse > for the switch itself. The Touch-Tone Register would connect to a > digit translator that inputs the 2-of-5 binary code directly into the > relays of the Originating Register (which can still receive dial > pulse). On Number 1 Crossbar and Panel however your DTMF would be > converted to 20 pulse per second dial pulsing. Only in Step-by-Step is > your DTMF converted down to "normal" 10 pulse per second dial pulsing; > though it should be noted that in step it either gets converted by a > "dumb" Touch-Tone Reciever Converter (DTMF goes in, dial pulse goes > out) in a direct control step, in a common control step (yes that was > a thing) the DTMF actually ends up getting converted in the same way > as on #5XB with the common control elements dial pulsing. > > > However it should be noted: Crossbar switches make noise when > connecting through the switch fabric; and depending on trunking and > the kind of switch you're calling you might hear dial pulsing, panel > call indicator pulsing, or revertive pulsing. RP would be sent on a > direct connection between a crossbar to a Number 1 Crossbar or Panel > switch (and to Number 5 Crossbar occasionally). PCI is something you'd > *never* hear in the 80s, since the only tandems that required PCI > (namely Panel Sender Tandem) were gone by the 70s, and the tandems > that replaced them (Crossbar Tandem) while it can still "speak" PCI > would be more likely to use MF tones; also end offices that would use > PCI, namely manual offices, were also dead and gone by the 80s. Dial > pulsing however... well that goes to step offices, and if you have a > step tandem anywhere in the chain (you could have a #5XB to #5XB call > which you'd think would be MF'd; but if you have a step tandem you get > dial pulse). > okay, this is _really interesting_. Where can I read more?