RE: The 931 exchange

[Garrett Wollman <wollman>]

<<On Thu, 24 Jan 2002 14:57:21 -0500, EM1 GITCHIER <RGITSCHIER@doyle.navy.mil> said:

> I don't know the real answer, but perhaps it could have something to do with
> tons of calls flooding contest lines (like THAT happens nowadays as compared
> to say, the 60s and 70s).

The ``choke'' feature was originally introduced by The Bell System in
the late 1970s, and was originally designed to serve along with the
900 SAC for ``mass calling'' features.  This system was only ever used
once on any significant scale, when then-President Carter did a live
phone-in program on one of the broadcast networks.  This feature was
originally implemented because public-safety authorities were
concerned that such mass-calling events would use up so much capacity
in the telephone network that emergency calls would not get through.

In this original use of the 900 SAC, callers from different areas were
directed to dial different numbers; in Massachusetts, the number was
900-931-xxxx.

When the 900 SAC became (in the immortal words of Mark Cuccia)
pay-Pay-PAY-per-call, this usage was dropped, and the ``exchange''
part of the 900 number was used to tell the telephone network how much
the call should cost.  However, the ``choke'' equipment which had been
installed in advance of the Carter broadcast was left in place, and
reconfigured to provide the ``contest line'' services we're familiar
with today.  In most cases, the same exchange code as was used for
900 service became the local choke exchange.

Nowadays, with electronic switching equipment, it is no longer
necessary to devote an entire exchange to this purpose; individual
numbers can be set up with the ``choke'' feature, and switches have
special processing for emergency calls which will bump other users
when necessary.  In any case, the tarriffs no longer encourage the use
of the choke feature (why pay telco to fix something when you could
not pay them and have telco be forced to fix it anyway?).  That's why
NEXT uses a number in the 617-423 exchange.  But, if you still have an
old ``choke'' number, particularly one of long standling like
617-931-1234 or 514-790-0231, then it's probably worth the cost of
maintaining the number to minimize caller confusion.

-GAWollman