Back in 1994, when I first started working at the happy pipes my erstwhile employer, Telecom New Zealand, was phasing out the last of its rural crossbar exchanges and party lines.
This is a video of a similar exchange in Melbourne, Australia filmed as it was being shut down in 1999. Never mind the size of thing, just listen to the noise it makes as it racks through calls and tolls – incredible:
Fast forward sixteen years and anyone can set-up their own Interactive Voice Response in ten minutes or less. The barrier to entry is now low enough for one person, a laptop and some hosted server space to offer a pretty decent smart PBX service, perhaps throw in some SMS too.
The call control and switching capabilities of a crossbar exchange are now available to all for free (Asterisk) or at a modest price from a vendor (Twilio, Voxeo etc.). Old school telecoms resellers have been reinvented as API telephony providers.
What a great time to be alive. Here endeth the not-so-ancient history lesson.