[comp.dcom.telecom] Fun With Step-By-Step Switches

djcl@uunet.uu.net> (03/20/90)

Years ago, when I had access to a real live step-by-step exchange,
there were some strange things that could be done.

For instance, because of number absorbing and things like that, a call
placed to one exchange for numbers of the form nxx.4xxx could also be
dialed using nxx.7xxx when called via long distance (same nxx
exchange, same last three digits, just use a 7 instead of a 4; there
were officially no such things as nxx.7xxx numbers). Some people kept
phoning our number long distance because they were really wanting some
party who had a number like zzz.7xxx in another exchange, only they
decided to dial our exchange (which was adjacent) as nxx.7xxx,
therefore getting us on nxx.4xxx.

Not to mention what we could do to that adjacent exchange (zzz)...
dialing to that exchange, but with numbers like zzz.70523 (yes, extra
digits on step-by-step!), it was possible to tap into some of the
calls being placed in that exchange. (Again, no official phone #s in
the zzz.70xx range, but this was something strange for electro-mechanical 
technology).

Of course, up in the great white north, one used to be able to dial 1
514 188 xxxx and it likely got the overseas dialing trunk.

No wonder the phone company wanted to switch us over to digital
technology as soon as possible. (I didn't have a blue box, so some of
these things couldn't be tested out too well). Obviously, with the
change in technology, all of the above is now likely unavailable.

Anyone else with experiences on SxS switches?


|| David Leibold          "The trouble with normal is it always gets worse"
|| djcl@contact.uucp                       - Bruce Cockburn