TELECOM Digest OnLine - Sorted: Re: Tie Lines (was Re: Foreign Exchange (FX) Lines Still in Use?

Re: Tie Lines (was Re: Foreign Exchange (FX) Lines Still in Use?
21 May 2005 20:17:44 -0700

Julian Thomas wrote:

> Before a unified "dial 8" IBM internal network, there were a multitude
> of codes for different locations. Some of them were of the "let your
> fingers find the way" where you dialled a code for one location, and
> then its code for an associated location.

Many organizations worked this way. For example, a department store
chain devoted several pages of its phone directory to how to dial
different stores and the main office -- every location had its own
code and they were non-symetrical. I suspect as location ons were
added or expanded, they were just added to whatever empty slots were
on individual store PBXs, which themselves were all unique.

> After the dial 8 network was put in place, you dialed 8 + 3 digits for
> location + 4 digits extension.

As the Bell Telephone network grew more "intelligent" they could do
more things. The 8+3+4 network you describe was used by many organi-
zations. The last 4 digits were the same that an outside caller used,
but the 3 digits were different. Number cards had both sets of 3
digit codes on them. The internal systems usually had some sort of
acronym name for them.

My own employer had that system but abandoned it in favor of cheap
long distance circuits. Previously the dial 8 circuits were often
busy or not working that well. Dial 8 calls were not accounted for,
but dial 9 calls were and this allowed for better control of calling
and reduction of personal calls.

> [TELECOM Digest Editor's Note: The Stanotel network of Standard Oil
> Company was really something in that regard, but the biggest I have
> ever seen -- with a seven digit dial in number from the 'outside
> world' and absolutely unprotected;

As mentioned, people could dial into distant PBXs via tie lines and
then dial outward on another tie line. Sometimes this was protected
and blocked, sometimes not. Indeed, it was allowed to enable outward
local calls instead of toll calls to a distant city or relays to
distant locations. One fellow, who worked for an outfit that had many
remote locations, told me of building a long chain through many towns.
He could hear his dial pulses being slowly relayed through.

Usually internal phone systems were pretty well isolated, and of
course the Centrex's of different organizations isolated. But
sometimes there were leaks:

Many organizations shared the exchange for their Centrex. That is
Org1 would be 222-2000 and -3000, and Org2 would be 222-5000, -6000,
and -7000. Obviously the separate organizations had to dial 9-outside
to communicate with each and not internally. Well, usually. I
happened to work for two different companies that shared the prefix.
Attempting to dial the other on Centrex wouldn't work. But, playing
around with Org1's tie line did get me into Org 2! I dialed the
remote location, then dialed back from that remote location (tie lines
didn't protect too often for that) and was able to get directly into
Org 2. (For those wondering, my job was incredibly boring and I
needed something to make the day go by.)

In electro-mechanical days, the cost of maintaining tie lines--
since they transmitted dial pulses and signals in both directions--
must have been substantial.

[TELECOM Digest Editor's Note: That same situation is true in Chicago.
City of Chicago's centrex system is 312-PIG-4000 and upward. Carson
Pirie Scott and Company department store is 312-744-2500 and downward.
But they are strictly separate. None of Carson's phones can get into
the city's phones or vice versa. City of Chicago had a switchboard on
RANdolph-8000 for about sixty years, then they decided to put all
the phones on centrex. This was back in the early days of the Viet
Nam war, the early 1960's, when people in Chicago (and most places
in the USA) were anti-everything-establishment. Illinois Bell had a
lot of phreaks and anti-war people working for them at the time, and
unlike today, where prefixes and area codes are in relatively short
supply and require some diligence in selection, in those days things
were so wide-open, zillions of prefixes available, etc.

City of Chicago asked for a centrex system; the guys at Bell started
working on it, and 'someone' chose 312-744 as the prefix to be used;
he and 'others in the _in-crowd_ winked about it and mutually agreed
to keep their mouths shut until it was too late to be changed. The
tables at AT&T get updated, new directories get printed for the entire
city (it was about the time of year to do that anyway), then that
'someone' let the _Chicago Seed_ in on the joke. The Seed was the
original anti-everything newspaper during the 1960s ... the Seed
decided as a 'public service' to print a new public directory of the
city offices, "so our readers will know how to reach their council
person, the mayor, city offices, police officials, etc. Midst a full
page in the Seed giving the new numbers to call, the Seed helpfully
noted, "To reach any Pig with whom you have business, under the new
phone system you only need to dial PIG and the Pig's four digit

Mayor Daley the First was furious about the whole thing; Illinois Bell
made sort of feeble apologies and explained that 'AT&T issues the
prefixes and codes, not us, and anyway it was all purely coincidental'
... over the next few years, _Illinois Bell_ cleaned up their house
quite a lot also. The Seed was the kind of newspaper the office clerks
in suits and ties working downtown would read on their way to/from
work, glancing around to see who was watching them read it, then
snickering at the stories they found therein. Everyone openly
condemmed the Seed, but loved to sneak reads from it, including the
infamous 'Directory of Pigs' issue. That was also the time when Mayor
Daley the First (father of the present guy holding the office) made
his rather stupid remark, "Our police officers are not Pigs! They are
human beans! And they demand respect, not disrespect!" As the VietNam
War progressed, and the two major riots in 1968 demonstrated, not
everyone agreed with the Mayor's assessment. Carson's Department Store
got moved in on 744 (in the lower group of digits) a few years later.

And _that_ is how City of Chicago came to have 312-744 for their
phones (but now, in 2005 they have not only 744, but 745, and 747 as
well.) PAT]

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