Re: Verizon selling off phone lines [Telecom]

On Thu, 14 May 2009 06:53:55 -0700 (PDT), wrote,

>***** Moderator's Note ***** >> I don't know why Verizon bought GTE: maybe they needed the Strowger >> pattents. ;-) > > IIRC, Panel was invented because Ma Bell refused to license > them. Once they expired, Ma started building steppers

In Southwestern Bell it was always understood that Bell Labs and Western Electric were primarily interested in large multi-office cities where common control capabilities were needed, and [were] not much interested in smaller places where SxS was not only adequate but in many ways superior.

Quite a few cities became all-SxS (starting with Automatic Electric SxS equipment), to their detriment when they grew to really need common control capabilities. Some of those cities were Los Angeles and much of southern California, Houston, Dallas, Oklahoma City, Tulsa and probably many others.

Los Angeles met the need by developing and installing SxS senders. Oklahoma City, when it reached that point, installed an SxS tandem, [because] an engineering study showed an SxS tandem was more economical and just as satisfactory as an XB tandem. Of course, the replacement of all [SxS] offices with (first) #5XB and (later) ESS took care of the problem.

Wes Leatherock

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Certainly SxS was superior for smaller offices. Common control required considerable overhead and was thus uneconomical in smaller offices.

Nonetheless, the Bell Labs history on switching documents many improvements made to the Strowger unit over the years, [to improve] SxS offices. [For example,] in the 1960s electronic front ends were added to improve efficiency.

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Before that Pacific Telephone, for one BOC, added a No, 5 XBAR unit as the common control unit for giant, old SxS offices (Pasadena and Los Angeles Madison come to mind) and the XBAR also served as a local office code expansion unit.

GTE, OTOH, [chose] this terrible "director" unit, which failed terribly under traffic loads, and this went on for years in the LA area. The subscriber could make a non-toll call just fine, but on a toll call he could wait up to 90 seconds for an ATB signal to appear.

***** Moderator's Note *****

I'd like to hear more about using a #5 for common control with a SxS office: I didn't know that was possible until now.

Bill Horne Temporary Moderator

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Sam Spade

Maybe I am phrasing it incorrectly. The #5 XBAR was placed in those large SxS offices to provide the routing of calls from the SxSes.

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